The Oral Cavity And Salivary Glands
Question 1. Write a short note on leukoplakia.
Answer:
Leukoplakia is defined as a predominantly white lesion of the oral mucosa that cannot be characterized as any other defiable lesion. WHO (1997)
Leukoplakia should be used to recognize white plaques of questionable risk having excluded (other) known diseases or disorders that carry no increased risk for cancer. Warnakulasuriya et al (2008)
Leukoplakia Etiology
- Tobacco: It is used by a large number of people in various forms such as smoking cigarettes, cigars, biddies and pipes.
- All these types of tobacco habits are important for the development of leukoplakia.
- It is believed that during smoking a large amount of tobacco end products are produced in the oral cavity.
- The products in association with heat cause severe irritation to the oral mucus membrane and finally result in the development of leukoplakia.
- Alcohol: Many people develop leukoplakia that consumes alcohol leukoplakia as well as use tobacco in some form.
- Candidiasis: Chronic candidal infections are associated with leukoplakia.
- Dietary Deficiency: A deficiency of vitamin A causes metaplasia and hyperkeratinization of epithelium which may result in the development of leukoplakia.
- Syphilis: Syphilitic infections play a minor role in the causation of leukoplakia.
- Hormonal imbalance: Imbalance or dysfunction of both male and female sex hormones causes keratogenic changes in oral epithelium.
- These changes lead to the development of leukoplakia.
Read And Learn More: Pathology Question And Answers
Leukoplakia Gross Features
- Lesions of leukoplakia appear white or whitish-yellow or red velvety of more than 5 mm diameter and are variable in appearance.
- Lesions are circumscribed, slightly elevated, smooth or wrinkled, speckled, or nodular.
Leukoplakia Histologically
Leukoplakia is of two types, i.e.
- Hyperkeratotic type: It is characterized by orderly and regular hyperplasia of squamous epithelium with hyperkeratosis on the surface.
- Dysplastic type:
- When cellular changes such as loss of stratification of epithelium, focal areas of increased and abnormal mitotic figures, hyperchromatism, pleomorphism, loss of polarity, and individual cell keratinization lesion are considered epithelial dysplasia.
- Mild dysplasia reverts back to normal offending etiologic factor is removed whereas severe dysplasia is indicative of progression into carcinoma.
- Histologically, leukoplakia is expressed as a hyperkeratotic simplex and hyperkeratotic complex.
- Hyperkeratoic simplex denotes mild leukoplakia and the chances of its malignant transformation are less while hyperkeratotic complex denotes severe leukoplakia and the chances of its malignant transformation are high.
- In leukoplakia there is often a variable degree of destruction of collagen fibers and moreover, chronic inflammatory cell infiltrate is also present in underlying connective tissue stroma.
Question 2. Write a short note on dental caries.
Answer:
Dental caries is an “irreversible progressive microbial disease of the calcified tissues of the teeth, characterized by the demineralization of the inorganic portion and distortion of the organic substances of the tooth, which often leads to cavitation”.
Dental caries Etiopathogenesis
- Miller’s chemical-parasitic theory proposes that acid formed due to the fermentation of dietary carbohydrates by oral bacteria leads to progressive decalcification of the tooth. Structures with subsequent degeneration of the organic matrix.
- The acidogenic theory states that the process of dental caries involves two stages.
Initial Stage
Production of organic acid occurs as a result of the fermentation of carbohydrates by the plaque bacteria.
Later Stage
The acid causes decalcification of enamel followed by dentin and thereby causes total destruction of these two along with a dissolution of their softened residues. The final result is cavity formation.
Dental caries Gross Features
- The earliest change is the appearance of a small chalky white spot on the enamel which subsequently enlarges and often becomes yellow or brown and breaks down to form a carious cavity.
- The cavity becomes larger due to fractures of an enamel. As the lesion reaches the enamel-dentin junction, the destruction of dentin also begins.
Dental caries Histopathology
Stromal elements are present as loose connective tissue and as a myxoid, mucoid, and chondroid matrix which stimulates cartilage, i.e. pseudo cartilage. However true cartilage and bone are also observed in a small proportion of this tumor.
Histopathological Features of Caries in Enamel
Early Enamel Caries
- There will be loss of inter prismatic or inter rod substances with an increase in prominence of these enamel rods.
- The dark line often appears at the right angles of the enamel rods, suggesting segments.
- Accentuation of the incremental striae of Retzus often occurs.
Advanced Enamel Caries
It presents several zones in the tissues, out of which four zones are clearly visible, starting from the inner advancing front of the lesion the zones are:
Zone 1: Translucent Zone
- It is the deepest zone that lies at the advancing front of the enamel lesion.
- This zone is more porous than normal enamel.
- The pores are larger than the normal enamel.
- The pore volume is 1%.
- This zone appears structureless.
- This zone contains more fluoride than normal enamel.
Zone 2: Dark Zone
- The dark zone is located just superficial to the translucent zone and its dark appearance is due to the excessive demineralization of the enamel.
- The zone is narrower in rapidly advancing caries and it is wider in slowly advancing lesions.
- The zone contains 2 to 4% pore volume.
- The pores are larger than normal but smaller than those of the translucent zone.
- This zone reveals some degree of remineralization of carious lesions.
Zone 3: Body of Leison
- The zone is situated between the dark zone and the surface layer of the enamel.
- It represents the area of greatest demineralization.
- The pore volume is 5 to 25%.
- This zone contains appetite crystals larger than those of normal enamel.
- The large crystals result from the reprecipitation of minerals dissolved from the deeper zone.
Zone 4: Surface Zone
The surface zone when examined by the polarizing light appears relatively unaffected, it may be due to the surface remineralization by the salivary mineral ions.
Histological features of caries in dentin/dentinal caries
Dentinal caries histologically present 5 zones in the carious region, which are:
Zone 1: Normal Dentin
- This zone represents the innermost layer of the carious dentin, here the dentinal tubules appear normal.
- There is evidence of fatty degeneration of the Tome’s process.
- No crystals in the lumen of the tubules.
- No bacteria in the tubules.
- Intertubular dentin has normal cross-banded collagen and normal dense apatite crystals.
Zone 2: Subtransparent Dentin
- This is the zone of dentinal sclerosis and is characterized by the deposition of very fie crystal structures within the dentinal tubules.
- The superficial layer shows area of demineralization and damage of the odontoblastic processes.
- No bacteria in the tubules.
- Dentin is capable of remineralization.
Zone 3: Transparent Dentin
- This zone appears transparent and this is because of the decalcification of dentin.
- It is softer than normal dentin.
- No bacteria in tubules.
- Cross-banded intertubular collagen is still intact.
- This zone is capable of self-repair and remineralization.
Zone 4: Turbid Dentin
- This zone is marked by the widening and distortion of dentinal tubules, which are packed with microorganisms.
- There is very little amount of minerals in dentin, and denaturation of collagen fibers also takes place.
- The zone cannot undergo self-repair or remineralization.
- This zone must be removed before restoration.
Zone 5: Infected Dentin
- This is the outermost zone of the carious dentin.
- It is characterized by complete destruction of dentinal tubules.
- In this zone, the area of decomposition of dentin, which occurs along the direction of dentinal tubules is called “Liquefaction foci of Miller”, which occur perpendicular to dentinal tubules and are called “Transverse Clefts”.
- In the process, the entire dentinal structures become destroyed and cavitation begins from the dentin enamel junction.
Dental caries Various Caries Activity Tests
Snyder Test
- This test measures the ability of salivary microorganisms to produce organic acids from carbohydrate metabolism.
- Glucose agar media containing an indicator dye, i.e. Bromocresol green is useful.
- The indicator dye changes from green to yellow in a range of pH between 5.4 to 3.8
- Paraffin-stimulated saliva is added into the medium, the change of the medium from green to yellow is indicative of the degree of caries activity.
Salivary Reductase Test
- It measures the activity of the Reductase enzyme present in salivary bacteria.
- Paraffin-stimulated saliva is collected in the plastic container and an indicator dye “Diazoresorcinol” is added to it which colors the saliva blue.
- The Reductase enzyme liberated by the cariogenic bacteria causes color changes in the medium from blue to other colors, which indicates caries’ “conduciveness” of the patients.
Dental caries Alban’s Test
It is the modification of the Synder test. It uses less agar i.e. 5 mL per tube. The saliva is drooled directly into the tubes and the tubes are incubated for 4 days at 37°C. The color change is noted from bluish-green to yellow and the depth to which the change has occurred is noted.
Dental caries Strip Test for S. mutans Level in Saliva
Saliva/plaque samples are obtained by using tongue blades and toothpicks (after air drying the tooth for plaque samples) and are transferred to the S. mutans strip which is incubated in MSB agar (Mitis Salivarius Bacitracin agar).
The number of S mutants colonies is used to estimate the caries activity and more than 105 colonies per mL of saliva is indicative of high caries activity.
Dental caries Buffer Capacity Test
10 mL of stimulated saliva is collected at least once after eating and stored under paraffin oil to prevent the loss of volatile bicarbonate ions, 4 mL of this is measured in a beaker.
After correcting the pH meter to room temperature the pH of the saliva is adjusted to 7.0 by the addition of acid or base. The level of lactic acid in the graduated cylinder is then again recorded.
Lactic acid is then added to the sample until a pH of 6.0 is reached. The amount of lactic acid needed to reduce ph from 7.0 to 6.0 is the measure of the buffer capacity.
Question 3. Write a short note on oral thrush.
Or
Discuss in short oral thrush.
Answer:
- Oral thrush is also known as pseudomembranous candidiasis.
- It is a superficial infection of the upper layer of the oral mucous membrane and results in the formation of patchy white plaque or flocks on the mucosal surface.
Oral thrush Pathogenesis
- Overgrowth of yeast on oral mucosa causes desquamation of oral epithelial cells and there is an accumulation of bacteria, necrotic tissue, and keratin.
- Debris combines to form pseudomembrane and adhere closely to the oral mucosa.
Oral thrush Etiology
- Hormonal disturbances
- Local or systemic steroids therapy
- Xerostomia
- Poor oral hygiene
- Denture wearing
- Heavy smoking
- Prolong antibiotic therapy.
Oral Thrush Laboratory Diagnosis of Candidiasis
- Fragments of plaque material are smeared on a microscopic slide, macerated with 20% potassium hydroxide, and examined for typical hyphae.
- Gram Stained smears from lesions or exudates show budding Gram-positive cells.
- The sample can also be cultured on Sabouraud’s broth and ordinary bacteriological culture. Colonies appear creamy white, smooth, and with a yeasty odor.
- Candida albicans alone form chlamydospores on cornmeal agar culture at 20°C.
- A rapid method of identifying Candida albicans is based on its ability to form germ tubes within 2 hours when incubated in human serum at 37°C.
- By the PAS method of staining Candida hyphae and yeasts should be recognized. The PAS method stains the carbohydrates of fungal cell walls and organisms are identified by bright magenta color. Hyphae are 2µm in diameter, vary in length, and may show branching.
Question 4. Write a short note on epulis.
Answer:
- Epulis is a fibrous growth of oral soft tissue and is very common.
- Epulis is a lesion that occurs on the gingiva and is localized hyperplasia of connective tissue following trauma or inflammation in the area.
Types of Epulis
- Congenital epulis
- Fibrous epulis
- Pregnancy epulis
- Giant cell epulis
- Myelomatous epulis
- Sarcomatous epulis
- Carcinomatous epulis.
Epulis Clinical Features
- It occurs at the age of 10 to 40 years.
- Female predilection is present.
- The most affected sits are the lip, gingiva, tongue, palate, and vestibule. The lesion is more common in the maxillary anterior region.
- The lesion is an elevated, pedunculated, or sessile mass with a smooth, lobulated, or warty surface that is ulcerated.
- On manipulation, the ulcer bleeds.
- The lesion is pink to red to purple in color depending on the age of the lesion. It is usually painless and is soft in consistency.
- The size of the lesion ranges from 1 mm to centimeters.
Epulis Histopathology
- The overlying epithelium is thin and atrophic. At times it is hyperplastic too.
- The surface of the epithelium is usually ulcerated and is replaced by thick fir in the purulent membrane.
- Underlying connective tissue has a number of endothelial-lined vascular spaces engorged with RBCs and extreme proliferation of fibroblasts and budding endothelial
cells. - There is a presence of moderate infiltration of PMN leucocytes, lymphocytes, and plasma cells.
- Areas of hemorrhage and hemosiderin pigmentation is seen in connective tissue stroma.
- Histologically epulis is known as pyogenic granuloma.
Question 5. Define adenoma. Discuss its causes.
Answer:
Adenoma is a benign epithelial tumor usually arranged like a gland.
The adenomas are of two types:
- Pleomorphic
- Monomorphic.
- Warthin’s tumor
- Oncocytoma
- Other types, i.e. myoepithelioma, basal cell adenoma, and clear cell adenoma.
Causes of Adenoma
- Tobacco chewing and tobacco smoking.
- Chronic alcohol consumption
- Human papillomaviral infection.
- Poor or dental hygiene
- Nutritional deficiency
- Exposure to sunlight, radiation
Question 6. Write a note on the pleomorphic adenoma of the salivary gland.
Or
Write a short note on the mixed parotid tumor.
Or
Write a short note on pleomorphic adenoma.
Answer:
Pleomorphic adenoma or benign mixed tumor is the most common neoplasm of salivary glands. The parotid gland is mostly affected by the tumor.
Pleomorphic adenoma Pathogenesis
- There is the presence of myoepithelial cells and reserve cells arranged in the intercalated duct.
- The intercalated duct reserve cells can differentiate into ductal and myoepithelial cells and the latter can then undergo mesenchymal metaplasia.
- Dardick’s theory: It is the most accepted theory. They state that a neoplastically altered epithelial cell with the potential for multidirectional differentiation may be histologically responsible for the pleomorphic adenoma.
Pleomorphic adenoma Clinical Features
- Pleomorphic adenoma develops in the 5th and 6th decade of life.
- It produces slow-growing, well-delineated exophytic growth of the salivary gland.
- The surface of the lesion is smooth and lobulated and generally, there is no pain.
- The neoplasm is usually soft or rubbery in consistency and is freely movable.
- The parotid gland lesion is usually superficial and often arises in the superficial lobe as a small mass overlying the angle of the mandible or anterior to the external ear.
- Sometimes, lesions can be multinodular and can assume an enormous size, especially in long-standing lesions.
- In buccal mucosa or lip pleomorphic adenoma presents small, painless, well-defied, movable nodular lesion with intact overlying mucosa.
Pleomorphic adenoma Gross Features
- Pleomorphic adenoma is a circumscribed, pseudo encapsulated, rounded, at times multilobulated fim mass, 2 to 5 cm in diameter, with a bosselated surface.
- The Cut surface is grayish-white and bluish, variegated, semitranslucent, usually solid, and occasionally may show some cystic spaces. Consistency is soft and mucoid.
Pleomorphic adenoma Histopathology
- The neoplasm often exhibits the proliferation of glandular epithelial cells in the form of diffuse sheets or clusters.
- The neoplastic cells are polygonal, spindle, or stellate in shape and have a tendency to form duct-like structures.
- The duct-like structures are of varying size, shape, and number and are widely distributed within lesions.
- Histologically, each duct-like structure exhibits an inner row of cuboidal or columnar cells and an outer row of spindle shape myoepithelial cells.
- The epithelial cells show “squamous metaplasia” and sometimes there may be the formation of keratin pearls by metaplastic epithelial cells.
- The connective tissue undergoes hyalinization to form structureless homogeneous material.
- A complete capsule is never present.
Question 7. Write a short note on squamous cell carcinoma.
Answer:
Squamous cell carcinoma is the most common malignant epithelial tissue neoplasm of the oral cavity. It is mostly derived from stratified squamous epithelium.
Squamous cell carcinoma Etiology
The following are the etiological factors that lead to squamous cell carcinoma:
- Tobacco smoking: Cigarettes, Bidis, Pipes, Cigars, and Reverse smoking.
- Use of smokeless tobacco: Snuffipping, Gutkha, Tobacco chewing, Tobacco as a toothpaste.
- Alcohol: Drinking spirits, Drinking wines, Drinking beers
- Diet and nutrition: Vitamin A, B-complex, and C deficiency, Nutritional deficiency with alcoholism.
- Dental factors: Chronic irritation from broken teeth, 3 fitting or broken prostheses.
- Radiations: Actinic radiation, X-ray radiation
- Viral infections: Herpes simplex virus (HSV), Human papilloma virus (HPV), HIV, Epstein-Barr virus (EBV)
- Chronic infections: Candidiasis, Syphilis
- Genetic factors: Oncogenes, Tumor suppressor
- PreExisting oral diseases: Lichen planus, Plummer Vinson syndrome, discoid lupus erythematosus, OSMF.
Squamous cell carcinoma Gross Features
Grossly squamous cell carcinoma has two features, i.e.
- More commonly an ulcerated growth with elevated growth and indurated margin is seen.
- Less often a raised fungating or polypoid verrucous lesion without ulceration is found.
Squamous cell carcinoma Clinical Features
- Carcinomas mostly occur in the 4th to 7th decades of life.
- Males are more commonly affected
- The lower lip is the most common site, the second most common site is the lateral border of the tongue. Among all intraoral sites, the dorsum of the tongue and hard palate are the least common sites for oral squamous cell carcinoma.
- The initial lesion may be asymptomatic or can be presented as a white or red nodule or fissure over the oral mucosa.
- Initially, the lesion is usually painless.
- More advanced lesions present either as a fast enlarging, exophytic or invasive ulcer or sometimes as a large tumor mass or a verrucous growth.
- The ulcerated lesion often shows persistent induration around the periphery with an elevated and everted margin.
Squamous cell carcinoma Histological Features
As per the histological grading by Broder’s Classification of Oral Squamous Cell Carcinoma.
Well-Differentiated Squamous Cell Carcinoma
- Most of the squamous cell carcinomas histologically belong to the well-differentiated category.
- In this lesson, the tumor epithelial cells to a large extent resemble the cells of the squamous epithelium both structurally and functionally.
- Tumor cells produce large amounts of keratin in the form of “keratin pearls”.
- Tumor cells invade the underlying connective tissue, where the cells proliferate further and give rise to the formation of many epithelial islands within the connective tissue stroma
- Tumor cells often exhibit dysplastic features like cellular pleomorphism, nuclear hyperchromatism, individual cell keratinization, altered nuclear-cytoplasmic ratio, loss of cohesion, etc.
Moderately-Differentiated Squamous Cell Carcinoma
- The tumor cells are usually more severely dysplastic than that of the well-differentiated type.
- Tumor cells produce little or no keratin and these cells exhibit a greater number of mitotic cell divisions.
- There is the formation of epithelial islands or cell nests, etc. is diminished since these tumor cells do not differentiate or mature as much as the well-differentiated type of cells do.
Poorly-Differentiated Squamous Cell Carcinoma
- In poorly differentiated squamous cell carcinoma, the malignant tumor cells produce no keratin.
- The tumor exhibits extensive cellular abnormalities with a lack of normal architectural patterns and loss of intercellular bridges between the tumor cells.
- Mitotic cell division is extremely high and because of this, the neoplastic cells are often very immature and primitive looking and it is often very difficult even to recognize them as squamous epithelial cells.
Question 8. Write a short note on the causes of submandibular lymphadenitis.
Answer:
The causes of submandibular lymphadenitis are as follows:
- The most common causes of lymph node enlargement are inflammatory and immune reactions
- Primary malignant neoplasms
- Metastatic tumor deposits
- In atypical Mycobacterium
- In Staphylococcus aureus adenitis
- In group A streptococcal pharyngitis
- Chronic diseases of the mucous membranes of the nasopharynx and tonsils, For Example. chronic tonsillitis, chronic sinusitis, peritonsillar abscess
- Osteomyelitis of the lower jaw or upper jaw
Question 9. Write a short note on apthous ulcers.
Answer:
Apthous Ulcers
Aphthous ulcer is the most common type of non-traumatic, ulcerative condition of the oral mucosa.
Apthous Ulcers Etiology
The exact etiology is not known and only the probable factors have been identified which are as follows:
- Genetic predisposition: The disease often affects several members of the same family and moreover identical twins are most frequently affected.
- Exaggerated response to trauma: The ulcer develops in those mucosal sites which are subjected to trauma in the past, For Example. toothpick injury.
- Immunological factors: The disease may occur due to some autoimmune reactions, or in patients with immunosuppression, For Example. AIDS. Some investigators believe it
is an immune complex-mediated type III or cell-mediated type 4 reaction. - Microbiologic factors: The disease may be caused by herpes simplex virus Type I or S. sanguis.
- Nutritional factors: Deficiency of vitamin B12, folate, iron, etc. often reported in patients with aphthous ulcers; moreover supplementation of these elements may cause
rapid recovery. - Systemic conditions: Behcet’s syndrome, Crohn’s disease, and Celiac disease are associated with increased incidences of aphthous ulcers.
- Hormonal imbalance: Hormonal change during the menstrual cycle may be associated with a higher incidence of aphthous ulcers.
- Nonsmoking: The disease almost exclusively occurs in non-smokers or people who have given up smoking recently.
- Allergy and chronic asthma: Allergic manifestations to any medicines or foods (For Example. nuts and chocolates, etc.) may lead to the development of an aphthous ulcer.
- Miscellaneous factors: Stress and anxiety.
Aphthous Ulcers Clinical Features
- Aphthous ulcers usually develop over the movable, nonkeratinized oral mucosa like the tongue (lateral borders), vestibule, lips, buccal mucosa, soft palate and flor of the mouth, etc.
- The highest incidence of the disease is reported during early adult life.
- Before the appearance of the ulcer, the involved area produces a burning or tingling sensation, but the ulcers are never preceded by vesiculations.
- These ulcers recur in an interval of about 3 to 4 weeks.
- Clinically aphthous ulcers present three recognizable forms, namely:
- Minor aphthous ulcers
- Major aphthous ulcers
- Herpetiform ulcers.
Minor Aphthous Ulcer
- It is the most common type of aphthous ulcer of the oral cavity and it appears episodically either as a single lesion or in clusters of 1 to 5 lesions.
- The ulcers are very painful, shallow, round, or elliptical in shape and they measure about 0.5 cm in diameter with a crateriform margin.
- The lesion is usually surrounded by an erythematous “halo” and is covered by a yellowish, fibrinous membrane.
- Minor aphthous ulcers mostly develop over the nonkeratinized mucosa, For Example. lips, soft palate, anterior fauces, the floor of the mouth, and ventral surface of the tongue (gland-bearing mucosa), etc.
- The ulcer lasts for about 7 to 10 days and then heals up without scarring but recurrence is common.
- New lesions may continue to appear during an attack for about 3-4 weeks period.
- Few lesions may be present in the mouth almost continuously.
Major Aphthous Ulcers
- Major aphthous ulcers are less common than the minor form of the disease.
- These are larger, 0.5 cm in diameter, and can be as big as several centimeters in diameter.
- Major aphthous ulcers are more painful lesions than the minor variety, and they persist in the mouth for longer durations as they take more time to heal.
- These lesions are considered to be the most severe among all types of aphthae and they often make the patients ill.
- Only one or two lesions develop at a time and are mostly seen over the lips, soft palate, fauces, etc. Besides involving the non-keratinized mucosa, major aphthous ulcers can involve the masticatory mucosa as well, such as the dorsum of the tongue and gingiva, etc.
- The ulcer appears crateriform (owing to its increased depth) and it heals with scar formation in about 6 weeks’ time.
- Few lesions may look like malignant ulcers, moreover, sometimes these lesions occur in association with HIV infections.
- Major aphthous ulcers often become secondarily infected and in such cases, the healing process is further delayed.
Herpetiform Ulcers
- Herpetiform type of aphthous ulcers produces recurrent crops of extremely painful, small ulcers in the oral mucosa, which resemble herpetic ulcers. However, these ulcers do not develop following vesiculations and exhibit no virus-infected cells.
- Their numbers vary from a few dozen to several hundred and each ulcer is surrounded by a wide zone of erythema.
- The size of these ulcers ranges between l to 2 mm in diameter only. However, on a few occasions, small ulcers coalesce together to form large irregular ulcers.
- The ulcers last for several weeks or months.
- Children in their late teens often suffer from this disease and the lesions occur in both gland-bearing mucosa as well as over-keratinized mucosa.
- The lesions usually heal up within l to 2 week time.
Question 10. Write a short note on submucous firosis.
Answer:
OSMF is defined as “An insidious chronic disease affecting any part of the oral cavity and sometime pharynx. Although occasionally preceded by and/or associated with vesicle formation, it is always associated with juxtaepithelial inflammatory reaction followed by fire-elastic changes in lamina propria, with epithelial atrophy leading to stiffness of oral mucosa and causing trismus and inability to eat.” Pindborg (1966).
Submucous fibrosis Etiology
The OSMF is caused due to:
- Excessive consumption of red chilies.
- Excessive “areca nut” chewing.
- Nutritive deficiency
- Immunological fractures
- Genetic factors
- Protracted tobacco use
- Patient with deficiency of micronutrients.
Submucous fibrosis Clinical Features
- It is caused during 20 to 40 years of age.
- Females are affected more than males.
- In OSMF fibrotic changes are frequently seen in the buccal mucosa, retromolar area, uvula, tongue, etc.
- Initially patient complains of a burning sensation in the mouth, particularly during taking hot and spicy foods.
- There can be excessive salivation, decreased salivation, and defective gustatory sensation.
- In the initial phase of the disease palpation of mucosa elicits a “wet leathery” feeling.
- In the advanced stage, the oral mucosa loses its resilience and becomes blanched and stifled and thereby causing trismus.
- Palpation of mucosa often reveals vertical fibrous bands.
Submucous fibrosis Histopathology
Microscopically OSMF reveals the following features:
- Overlying hyper keratinized, atrophic epithelium often shows flattening and shortening of rete pegs.
- There can be variable degrees of cellular atypia or epithelial dysplasia.
- In OSMF dysplastic changes are found in epithelium which include nuclear pleomorphism, severe intercellular edema, etc.
- The stromal blood vessels are dilated and congested and there can be areas of hemorrhage.
- The underlying connective tissue stroma in an advanced stage of the disease shows homogenization and hyalinization of collagen fibers.
- Decreased number of fibroblastic cells and narrowing of blood vessels due to perivascular fibrosis are present.
- There can be the presence of signet cells in some cases.
Submucous fibrosis Treatment
- Stop areca nut and tobacco chewing strictly.
- Definitive treatment of OSMF includes intralesional injection of collagenase, corticosteroids, fibrinolysin, etc.
- Systemic administration of steroids in severe cases.
Question 11. Write a note on precancerous lesions.
Answer:
Precancerous lesions are defined as morphologically altered tissue in which cancer is most likely to occur than in its apparently normal counterpart.
- Leukoplakia
- Erythroplakia
- Mucosal changes associated with smoking habits
- Carcinoma in situ
- Bowen disease
- Actinic keratosis, cheilitis, and elastosis.
Question 12. Write a short note on basal cell carcinoma.
Answer:
Basal cell carcinoma is a common locally aggressive non-metastatizing malignant neoplasm of skin that is composed of a medullary pattern of basaloid cells.
Basal cell carcinoma Clinical Features
- Basal cell carcinoma develops mostly in middle-aged people, preferably in the 4th decade of life.
- Males are more commonly affected than females.
- The neoplasm commonly occurs over the hair-bearing areas of facial skin. The orofacial areas particularly vulnerable to these lesions are the upper lip, nasolabial folds, periorbital region, cheek, forehead, ear, etc.
- The neoplasm initiates as a slow-growing, firm, slightly elevated, small nodule.
- It gradually enlarges and develops a central crusted ulcer with an elevated, smooth, rolled border.
- There may be intermittent bleeding from the ulcer.
Basal cell carcinoma Gross Features
- Grossly the most common pattern is noduloulcerative basal cell carcinoma in which a slow-growing small nodule undergoes central ulceration with pearly, rolled margins.
A tumor enlarges in size by burrowing and destroying the tissues locally like a rodent and so it is named as rodent ulcer. - Less frequently non-ulcerated nodular patterns, pigmented basal cell carcinoma, and firosingvariants are encountered.
Basal cell carcinoma Histopathology
- Histologically, basal cell carcinoma is characterized by neoplastic proliferation of basaloid epithelial cells in the form of multiple solid islands or strands.
- These cells arise from the basal cell layer of the epidermis and they invade into the underlying dermis.
- The cells in the periphery of the tumor islands are columnar in shape and they often resemble the basal layer of the oral epithelium with hyperchromatic nuclei.
- These tumor cells do not show any feature of abnormal mitosis.
- The cells are uniform in shape and size and in their staining reaction. Moreover, these cells often have a palisaded arrangement.
- The central cells of the tumor islands may be polyhedral, oval, round, or even spindle-shaped.
- The fibrous connective tissue stroma reveals varying degrees of cellularity and it contains a large number of elastic fibers.
Question 13. Write in brief tumors of the salivary gland.
Answer:
WHO 2017 Classification of Salivary Gland Tumors
Malignant Tumors
- Mucoepidermoid carcinoma 8430/3
- Adenoid cystic carcinoma 8200/3
- Acinic cell carcinoma 8550/3
- Polymorphous adenocarcinoma 8525/3
- Clear cell carcinoma 8310/3
- Basal cell adenocarcinoma 8147/3
- Intraductal carcinoma 8500/2
- Adenocarcinoma, NOS 8140/3
- Salivary duct carcinoma 8500/3
- Myoepithelial carcinoma 8982/3
- Epithelial – myoepithelial carcinoma 8562/3
- Carcinoma ex pleomorphic adenoma 8941/3
- Secretory carcinoma 8502/3
- Sebaceous adenocarcinoma 8410/3
- Carcinosarcoma 8980/3
- Poorly differentiated carcinoma
- Undifferentiated carcinoma 8020/3
- Large cell neuroendocrine carcinoma 8013/3
- Small cell neuroendocrine carcinoma 8041/3
- Lymphoepithelial carcinoma 8082/3
- Squamous cell carcinoma 8070/3
- Oncocytic carcinoma 8290/3
Uncertain malignant potential
- Sialoblastoma 8974/1
Benign Tumors
- Pleomorphic adenoma 8940/0
- Myoepithelioma 8982/0
- Basal cell adenoma 8147/0
- Warthin tumor 8561/0
- Oncocytoma 8290/0
- Lymphadenoma 8563/0
- Cystadenoma 8440/0
- Sialadenoma papilliferum 8406/0
- Ductal papillomas 8503/0
- Sebaceous adenoma 8410/0
- Canalicular adenoma and other ductal adenomas 8149/0
Non-neoplastic Epithelial Lesions
- Sclerosing polycystic adenosis
- Nodular oncocytic hyperplasia
- Lymphoepithelial sialadenitis
- Intercalated duct hyperplasia
Benign Soft Tissue Lesions
- Hemangioma 9120/0
- Lipoma/sialolipoma 8850/0
- Nodular fasciitis 8828/0
Haematolymphoid Tumors
- Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) – 9699/3
These new codes were approved by the IARC/WHO Committee for ICD-0.
Secondary Tumors
Salivary Gland Description of Tumors of Salivary Gland
Pleomorphic Adenoma
- It presents as painless swelling at the angle of the jaw.
- The most common location is a superficial lobe of the parotid gland which is followed by the submandibular gland.
- The tumor is often diagnosed in the fourth to sixth decades of life and is uncommon in children.
- Females are more frequently affected.
- Grossly, pleomorphic adenoma is as mall, well-demarcated, round, and multilobulated lesion. Pleomorphic adenoma is typically solid but the cut surface has a variegated appearance; may be gray-white, myxoid with blue, translucent pseudochondroid areas.
Salivary Gland Microscopic Features
- Pleomorphic adenomas show both epithelial and mesenchymal differentiation
- Epithelial components, i.e. ductal and myoepithelial cells form ducts, acini, tubules, strands, or sheets. Ductal cells are cuboidal and myoepithelial cells are flattened or spindle shape.
- In pleomorphic adenoma background stroma can be mucoid, myxoid, pseudochondroid, or hyaline.
Salivary Gland Warthin’s Tumor
- It is also known as papillary cystadenoma lymphomatous and is a benign tumor seen in the parotid gland.
- It affects males in the fifth to seventh decades of life.
- It is thought to arise from heterotopic salivary tissue trapped in a regional lymph node during embryogenesis.
Grossly it is small, round to oval, lobulated, and encapsulated. Mucin containing narrow cysts or cleft-like spaces showing papillary projections can be seen on the cut surface.
Salivary Gland Microscopic Features
- The tumor is composed of epithelial and lymphoid tissue.
- The lesion is an adenoma undergoing cyst formation with papillary projections in cystic spaces.
- Lymphoid matrix exhibit germinal centers.
- A cyst is lined by a bilayered oncocytic epithelium, the inner cells of which are tall columnar with fine granular and eosinophilic cytoplasm and slightly hyperchromatic
nuclei. The outer layer consists of basaloid cells. - An eosinophilic coagulum is present within the cystic spaces.
- The numerous lymphocytic component may represent normal lymphoid tissue within which the tumor is developed.
Salivary Gland Monomorphic Adenoma
- It is similar to pleomorphic adenoma, except it does not contain a mesenchymal stromal component.
- This tumor is more common in minor salivary glands (For Example, upper lip), is bilateral in about 10% of cases.
- Various monomorphic adenomas are basal cell adenoma (most common), canicular adenoma, myoepithelioma adenoma, clear cell adenoma, membranous adenoma, and glycogen-rich adenoma.
Salivary Gland Mucoepidermoid Carcinoma
- It is the most common malignant tumor of the parotid gland and the second most common malignancy (adenoid cystic carcinoma is more common) of the sub-mandibular
and minor salivary glands. - Grossly some of the mucoepidermoid carcinomas appear well-circumscribed and may be partially encapsulated. Others are poorly defined and are infiltrative. The cut surface of the tumor may contain solid areas, cystic areas, or both. The cystic spaces contain viscous or mucoid material.
- Microscopically mucoepidermoid carcinoma is characterized by the presence of two types of cells, i.e. mucous cells and epidermoid squamous cells, the proportion of which helps to define the grade of the tumor, i.e. low grade (well differentiated), intermediate grade or high grade (poorly differentiated).
- The low-grade tumor has prominent cystic structures and proportionally more mucous cells, which may form gland-like structures and very few epidermoid cells.
- Intermediate-grade tumors show fewer cysts and a substantial solid component. There is an increasing proportion of epidermoid cells and occasional keratin pearl formation.
- High-grade carcinomas are solid tumors comprised mainly of epidermoid cells and show prominent cellular atypia and mitoses.
Salivary Gland Adenoid Cystic Carcinoma
- It is seen mainly in the fifth decade of life and presents as a gradually enlarging salivary mass, which can be accompanied by pain and paresthesia.
- Grossly, the tumor appears well-defied but unencapsulated. In the late stages, the tumor can be seen infiltrating the surrounding normal tissue. Adenoid cystic carcinoma is
is solid in consistency and rarely displays cystic spaces on the cut surface. - Microscopically the tumor consists of epithelial and myoepithelial cells variably arranged in tubular, cribriform, and solid patterns. The cribriform pattern is the most common and is easily recognizable.
- It is often referred to as the Swiss cheese pattern. Tumor cells are arranged in nests around cylindrical spaces that may contain a mucinous or hyalinized material.
- Cells that are arranged in layers and form ductal structures characterize tubular patterns. The solid pattern contains sheets of tumor cells with no intervening spaces.
Salivary Gland Acinic Cell Carcinoma
- It is a rare tumor that accounts for about l% of all salivary neoplasms.
- It is present in the fifth decade of life and is more common in women.
- The most common presentation is that of an asymptomatic enlarging mass.
- Grossly it demonstrates a mass that is well-circumscribed but lacks a true capsule.
- Microscopically it is a malignant neoplasm demonstrating serous acinar cell differentiation. Acinar cells are large, polygonal with lightly basophilic, granular cytoplasm and round, eccentric nucleus.
Question 14. Write a short note on carcinoma in situ.
Answer:
This is also called intraepithelial carcinoma.
- Carcinoma in situ is a condition that arises frequently on the skin but also occurs on mucus membranes including those of the oral cavity.
- Metastasis is impossible in intraepithelial carcinoma.
- Bowen’s disease is a special form of intraepithelial carcinoma occurring with some frequency on the skin, particularly in patients who have had arsenic therapy and is often associated with the development of internal or extracutaneous cancer.
Carcinoma in situ Histological Features
- Keratin may or may not be found on the surface of the lesion but, if present, is more apt to be parakeratin rather than ortho-keratin.
- In some instances, there appears to be hyperplasia of the altered epithelium while in others there is atrophy.
- An increased nuclear/cytoplasmic ratio and nuclear hypo or hyperchromatism are sometimes seen.
- Cellular pleomorphism is uncommon
- There is a loss of orientation of cells and a loss of their normal polarity.
- Sometimes a sharp line of division between normal or altered epithelium extends from the surface down to the connective tissue rather than a blending of epithelial changes.
Question 15. Write a short note on the dentigerous cyst.
Answer:
It is also known as a follicular cyst.
Dentigerous cyst Pathogenesis
- Intrafollicular Theory: Dentigerous cyst is caused by a fluid accumulation between reduced enamel epithelium and enamel surface which results in a cyst in which the crown is located within the lumen.
- Extrafollicular Theory: Dentigerous cyst may arise by proliferation and cystic transformation of islands by odontogenic epithelium in a connective tissue wall of a dental follicle or even outside dental follicle and this transformed epithelium then unite with lining follicular epithelium forming cystic cavity around tooth crown.
Dentigerous cyst Radiographic Features
A dentigerous cyst reveals a unilocular radiolucent area which is associated with the crown of an unerupted or impacted tooth. There are various radiographic types which are given by Thoma.
- Central Variety: In this, the crown is enveloped symmetrically. The pressure which is applied by the cystic fluid to the crown of the tooth may push the tooth away from its direction of eruption.
- Lateral Variety: In this, the radiographic appearance of the dentigerous cyst occurs due to the dilatation of the follicle on one aspect of the crown. This is associated with mesioangular impacted mandibular third molars which are partially erupted.
- Circumferential Variety: In this, the complete tooth is enveloped by the cyst.
Dentigerous cyst Histologic Features
Non-inflamed Dentigerous Cyst
- H&E stained section shows stratified squamous epithelium which is 2 to 4 cell layer thick and lines the lumen.
- Rete peg formation is absent. So the epithelium connective tissue interface is flat.
- The fibrous connective tissue wall is loosely arranged.
Inflamed Dentigerous Cyst
- H&E stained section shows stratified squamous epithelium which shows varying amounts of hyperplasia.
- Small islands or cords of inactive appearing odontogenic epithelial rests at times present in the fibrous walls.
- Rete peg formation is present.
- Focal areas of mucous cells are also seen in the epithelium of dentigerous cysts.
- Rarely the ciliated columnar cells are seen in the epithelium. Very rarely small nests of sebaceous cells are seen in fibrous cyst walls.
- Rushton bodies are present in epithelium. Rushton bodies are linear, curved, hyaline bodies which show variable stainability and have an uncertain origin.
- The connective tissue wall is thick and consists of loose fibrous connective tissue or sparsely collagenized myxomatous tissue.
- There is the presence of chronic inflammatory cell infiltration which consists of lymphocytes and plasma cells.
- Cystic lumen consists of a thin watery yellow fluid that is occasionally blood-tinged.
Question 16. Write a short note on sialadenitis.
Answer:
Inflammation of the salivary gland which mainly involves acinoparenchyma of the gland is known as sialadenitis.
Sialadenitis Etiology
Infectious Causes
- Viral infections are commonly involved, which include mumps—params, xo coxsackie A, choriomeningitis, parainfluenza, and cytomegaloviruses.
- Most bacterial infections arise as a result of ductal obstruction or decreased salivary flow, allowing the retrograde spread of bacteria throughout the ductal system.
- Blockage of the duct can be caused due to sialolithiasis, congenital strictures, or compression by an adjacent tumor.
- Decreased salivary flow may also be due to dehydration, debilitation, medication, recent surgery, or acute parotitis.
Sialadenitis Noninfectious Causes
Sjogren’s syndrome, sarcoidosis, radiation therapy, malnutrition, renal failure, and various allergens.
Sialadenitis Clinical Features
- It occurs during 20-40 years.
- It is located in the parotid salivary gland, submandibular salivary gland, and minor salivary glands.
Sialadenitis Signs and Symptoms
- Acute bacterial sialadenitis
- The affected gland will be swollen and painful.
- The overlying skin may be warm and erythematous.
- An associated low-grade fever and trismus may be present.
- A purulent discharge is observed from the duct orifice when the gland is massaged.
- Chronic bacterial sialadenitis
- It is commonly caused by recurrent or persistent ductal obstruction of Warthin’s duct. Periodic swelling and pain occur within the affected gland, usually developing at mealtime when salivary flow is stimulated.
Sialadenitis Histopathology
- Accumulation of neutrophils is observed within the ductal system and acini.
- Chronic sialadenitis is characterized by scattered or patchy infiltration of parenchyma by lymphocytes and plasma cells.
- Atrophy of acini is common.
Sialographic Features
- It demonstrates ductal dilatation proximal to the area of obstruction.
- Stenson’s duct may show a characteristic sialographic pattern known as sausage which reflects a combination of dilatation plus ductal strictures from scar formation.
Question 17. Write short note on lichen planus.
Answer:
Lichen planus is a precancerous condition.
It is a common mucocutaneous disease that arises due to an abnormal immunological reaction and the disease has some tendency to undergo malignant transformation.
Etiopathogenesis of Lichen Planus
- Oral lichen planus is a T cell-mediated autoimmune disease in which cytotoxic CD8 + T cells trigger the apoptosis of oral epithelial cells. The CD8 + lesional T cells may recognize the antigen associated with major histocompatibility complex (MHC) class 1 on keratinocytes. After antigen recognition and activation, CD8 + cytotoxic T cells may trigger keratinocyte apoptosis. Activated CD8 + T cells may release cytokines that attract additional lymphocytes.
- As per the recent studies in psychoneuroimmunology psychosomatic stress results in autoimmunity reactions and this leads to lichen planus.
Lichen planus Clinical Features
- It occurs among middle-aged and elderly people.
- There is a slight predilection for the females.
- Lichen planus can involve several areas of the oral cavity. Oral lesion: Mucosal surface of buccal mucosa, vestibule, tongue, lips, floor of mouth, palate, and gingiva.
- The patient may report a burning sensation in the oral mucosa.
- The oral lesion is characterized by radiating white and gray velvety thread-like papules in linear, angular, or retiform arrangement; tiny white elevated dots are present at the intersection of white lines known as “Wickham’s striae”.
Lichen planus Histopathology
- Overlying surface epithelium exhibits hyper orthokerati nation or hyper para keratinization or both.
- Acanthosis of the spinal cell layer is present.
- Shortened and pointed rete pegs of epithelium produce a “Sawtooth” appearance.
- Intercellular edema in the spinous cell layer is present.
- There is the presence of necrosis or liquefaction degeneration of the basal cell layer of epithelium.
- Few rounded or ovoid, amorphous eosinophilic bodies are present which are known as “Civatt bodies”.
- These Civatt bodies represent dead keratinocytes or other necrotic epithelial components which are transported to connective tissue for phagocytosis.
- Chronic inflammatory cell infiltration is present in the juxta epithelial lesion.
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