Cáncer tiroídeo tipo intermedio folicular-medular; una forma inhabitual, particular y agresiva: comunicación de tres casos / Mixed medullary and follicular carcinoma of the thyroid: report of three cases

Mixed medullary and follicular carcinomas of the thyroid shares secretory and immunohistochemical features of both follicular and parafollicular thyroidal cells. We report three women, aged 34, 63 and 61 old with this type of tumor. Its diagnosis must be bore in mind in patients with thyroidal tumors and a histological appearance of a medullary or undifferentiated carcinomas. An early diagnosis of a mixed medullary and follicular carcinomas of the thyroid is important, considering its special treatment and negative prognosis

Medullary thyroid carcinoma: Immunohistochemical and ultrastructural study

11 cases of medullary thyroid carcinomas [MTC] were evaluated in relation to the pattern, immunohistochemistry and electron microscopy. Six cases were classified as classical MTC with histochemical evidence of amyloid and 5 cases were atypical without histochemical evidence of amyloidosis. Immunostaining for thyrocalcitonin was positive in 4 out of 6 classical and 2 out of 5 atypical MTC cases. The neurosecretory granules were found in both the typical and the atypical MTC cases. The ultrastructural study is essential in the diagnosis of MTC, specially where the histological and immunohistochemical evaluation is not definite