Anaplastic Carcinoma
Incidence 10–12% of cases.
Anaplastic Carcinoma Clinical features
- Common in elderly women around 60–70 years of age.
- The majority of the patients present with rapidly growing thyroid swelling of short duration. The surface is irregular and consistency is hard.
- Early infiltration of the trachea results in stridor (scabbard trachea).\
- Infiltration of carotid sheath: In such cases, common carotid artery pulsation will not be palpable which is described as Berry sign positive.
- Early fixity is characteristic. Thus, the resectability rate is almost nil.
Anaplastic Carcinoma Thyroid
- The most rapidly growing thyroid malignancy
- Advanced age group at presentation
- The advanced nature of the presentation
- Gross local infiltration—Berry’s sign positive
- No form of treatment is successful
- Intrinsic carcinoma of the larynx spreading outside and infiltrating the skin should be considered as a differential diagnosis.
Read And Learn More: Clinical Medicine And Surgery Notes
Anaplastic Carcinoma Thyroid Diagnosis
It is established by FNAC.
Anaplastic Carcinoma Thyroid Treatment
- Due to the gross local infiltration into the vital structures in the neck such as the common carotid artery and trachea, the resectability rate is low.
- However, very rarely a surgeon will get an opportunity to excise isthmus so as to relieve compression of the trachea.
- Postoperative radiotherapy is given as a palliative treatment.
- In many cases, death occurs within 6 to 8 months.
Medullary Carcinoma Of The Thyroid (Mct)
- These tumours arise from parafollicular ‘C’ cells which are derived from ultimobranchial bodies and not from thyroid follicles.
- These tumours present in two different ways.
- Sporadic is common, seen in about 80–90% of cases.
- Familial variety presents as a part of Multiple Endocrine Neoplasia (MEN).
- It does not arise from the thyroglossal cyst.
Men Type 1
- Pituitary adenoma
- Parathyroid adenoma
- Pancreatic adenoma.
Men Type 2a
- Parathyroid adenoma
- Phaeochromocytoma
- Medullary carcinoma of the thyroid
- When it is associated with mucocutaneous neuromas involving lips, tongue, and eyelids, it is called Sipple syndrome, with an occasional marfanoid habitus (Men type 2b) It has a characteristic amyloid stroma.
- It presents as a solid, hard, nodular tumour
- These tumours are not hormone-dependent and do not take up radioactive iodine.
Calcitonin And Medullary Carcinoma Thyroid
- Not measurable in normal persons
- MCT produces very high levels
- Tumour marker of MCT
- Level decreases after thyroidectomy
- Level increases in case of recurrence
- Prophylactic thyroidectomy in relatives if calcitonin levels are high
Hormones Produced by MCT
- Calcitonin
- Prostaglandins
- Serotonin (5-HT)
- ACTH.
Spread
Both by lymphatics and blood, thus, worsening the prognosis.
Hormones Produced by MCT Treatment
Before proceeding with surgery, look for an associated phaeochromocytoma.
- Near-total thyroidectomy or total thyroidectomy
- The lymph nodes are treated by radical block dissection because they are fast-growing when compared to papillary carcinoma.
Genetic screening
All patients with medullary Ca thyroid must be screened for RET point mutation on chromosome 10. If +ve, their children should undergo prophylactic thyroidectomy prior to age 6.
If there are multiple secondaries in the bone, oral radioiodine has no role because this tumour does not arise from the thyroid cells. Only palliative radiotherapy can be given.
Malignant Lymphoma
- It is rare. Hashimoto’s thyroiditis can predispose to malignant lymphoma.
- Older patients are commonly affected.
- The tumour can present as rapidly growing, large thyroid swelling (primary lymphoma).
- Sometimes, they can appear as a part of generalised lymphoma (non-Hodgkin’s variety).
- FNAC can give the diagnosis.
- It is interesting to note that lymphomas of the thyroid respond very well to chemotherapy or radiotherapy.
Medullary Carcinoma Thyroid
- Arrises from parafollicular cells
- Calcitonin is the tumour marker
- Think of familial variety when a case of medullary carcinoma thyroid is diagnosed.
- Look for parathyroid enlargement and adrenal swelling (ultrasound of the neck and abdomen).
- Total thyroidectomy and radical block dissection of the neck should be done when the lymph nodes are enlarged.
Clinical Criteria For The Diagnosis Of Carcinoma Of Thyroid
- A thyroid swelling which is rapidly growing.
- Thyroid swelling with lower deep cervical lymph nodes and lymph nodes in the posterior triangle (papillary carcinoma thyroid).
- Hard gland, fixed to the trachea—anaplastic carcinoma of the thyroid.
- Thyroid swelling with a rapidly growing vascular, pulsatile swelling, commonly in the skull (follicular carcinoma).
- Thyroid swelling with hoarseness of the voice indicates infiltration of recurrent laryngeal nerve which is a feature of malignancy.
- Thyroid swelling with Berry sign positive (anaplastic carcinoma of the thyroid).
- Kocher’s test positive may be an indication of infiltration into the trachea.
Solitary Nodule Thyroid Gland
Almost all of the thyroid swellings initially can present as a solitary nodule. However, puberty goitres, colloid goitres, and diffuse toxic goitres produce uniform enlargement of the thyroid gland.
Multinodular goitre (MNG) presents as multiple nodules. However, very often a solitary nodule on clinical examination, may turn out to be a multinodular goitre at exploration. The solitary nodule has a higher incidence of malignancy when compared to MNG.
Causes of solitary nodule thyroid gland
- In 50% of the cases, a clinically palpable solitary nodule is a part of multinodular goitre
- Toxic autonomous nodule
- Adenoma
- Carcinoma
- Cysts
Solitary Nodule Thyroid Gland Management
- Ultrasound of the thyroid gland is an extremely useful investigation in the evaluation of solitary nodules.
- The solitary nodules should be investigated with a radio-iodine scan. The presence of a cold nodule raises the suspicion of malignancy. However, haemorrhage, thyroiditis, and cysts are the other causes of cold nodules.
Ultrasound And Solitary Nodule
- It can detect cysts
- Can guide FNAC
- Cyst larger than 3 cm, has a 14% chance of malignancy
- Hypoechoic pattern, incomplete peripheral halo, irregular margin and micro-calcification are suggestive of carcinoma
- Once the ultrasound is done, they are subjected to a fine needle aspiration cytology (FNAC).
- If FNAC proves the diagnosis of malignancy as in papillary carcinoma thyroid, near-total thyroidectomy is done.
- If there is a doubt regarding a follicular neoplasm in FNAC, a frozen section is arranged.
- If there is a toxic goitre diagnosed by high pulse rate and increase in T3, and T4 levels, an I131 scan can demonstrate a hot nodule.
- Histological diagnosis can be made by FNAC. Simple adenomas present as warm nodules in the isotope scan. Diagnosis is confirmed by FNAC and they are treated by hemithyroidectomy
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