Pathological Morphology and Prognosis on 29 Cases of Medullary Thyroid Carcinoma

Histological and immunohistochemical studies of 29 cases of medullary thyroid carcinoma were presented.All tumors were classified as six histologic subgroups,i.e.nestlike,fascicular,carcinoid,trabecular,diffuse and glandular type.In 22 cases(75.9%),there was amyloid in the stroma(as determined by Congo Red Staining).The immunohistochemical results showed both keratin and calcitonin positive in 29 cases;26 chromogranin A positive;22 NSE positive;21 CEA positive and 29 thyroglobulin negative.Twenty-three cases were followed-up for 2.4 to 16.6 years.Statistically,the favourable prognoses were seen in female patients,patients lesser than 40 years old and patients with a high frequency(>50%) of calcitonin-immunoreactive tumor cells.