Which of the following is/are true about medullary carcinoma of thyroid? 1. Arises from parafollicular cells 2. Amyloid stroma is present on histology 3. 10-25% cases are familial 4. Diarrhoea occurs 5. Total thyroidectomy is performed
MCT accounts for 5-10% of thyroid cancers, 80% of tumours are sporadic, and 25% occur as a pa of an autosomal dominant hereditary syndrome ( MEN 2A or 2B). Sporadic MTC often presents in the fifth decade as a unilateral solitary nodule. Patients with familial MTC more commonly present in the fouh decade with multifocal nodules in the upper poles or both thyroid lobes, where there is the greatest concentration of the cells. The malignancies involves the parafollicular cells, or C cells, derived from the neural crests. MCT is associated with the secretion of a biologic marker, calcitonin. Excess secretion of calcitonin has been demonstrated to be an effective marker for the presence of MCT. Calcitonin excess is not associated with hypocalcemia. Histologically, MCT is an ill-defined, nonencapsulated, invasive mass composed of spindle shaped or rounded cells separated by fibrous septa and amyloid deposits. Positive immunohistochemical staining for calcitonin, carcinoembryonic antigen, and amyloid aids in the diagnosis of MTC. A patients with a sporadic medullary carcinoma may have either of two manifestations: a palpable mass for which a diagnosis can be made with FNAC or the finding of an elevated calcitonin level. family members of patient with MEN-2 ideally screened for RET proto-oncogenes. The surgical approach to sporadic medullary medullary carcinoma involves at least total thyroidectomy with or without central lymph node dissection. Total thyroidectomy allows complete removal removal of the gland and a search for multicentricity. In sporadic MTC, the lesion is generally contained within one lobe, whereas in MEN 2, the malignancy involves the upper halves of both lobes. Age > 50 years at diagnosis, metastasis at the time of diagnosis, and association with MEN 2B are associated with poor prognosis. 70% of the patients with MEN 2B have metastasis at the time of diagnosis of medullary carcinoma thyroid out of which approximately less than 50% survive up to 5 years. Quotes from Love and Bailey (Ref: Given Below) "some cases are familial, possibly accounting for 10-20% of all cases". "diarrhea is a feature in 30% of cases and this may be due to 5- hydroxytryptamine or prostaglandins produced by tumour". Ref: L & B 25/e, Page 798 ; Sabiston 18/e, Page 941-42 ; CSDT 11/e, Page 306
1,2,3 true and 4,5 false
1,2,4 true and 3,5 false
4,5 true and 1,2,3 false
All are true