Medullary thyroid microcarcinoma: A clinicopathologic retrospective study of 38 patients with no prior familial disease

Thirty-eight patients (25 women, 13 men; mean age, 57.8 [32 to 91]) showing one or more medullary thyroid microcarcinomas (ie, <1 cm), with no prior M EN II or medullary thyroid carcinoma history in their family, were reviewed . Follow-up was available for 29 patients (mean, 53.6 months [1 to 147]). 2 1 patients (72.4%) are alive and free of disease, four patients (13.8%) die d during follow-up without disease, 2 patients are alive with disease (loca l recurrence and persistent hypercalcitoninemia) after 80 and 99 months, re spectively, and 2 patients died of disease after 24 and 46 months. Most tum ors were incidental pathological findings (19 of 38) or were discovered by systematic blood calcitonin measurement for a nodular thyroid disease (15 o f 38). Only the four patients who had an unfavorable outcome were symptomat ic cases (palpable micro-MTC, diarrhea, cervical lymph node metastasis and pulmonary metastatic disease). The two patients with metastatic disease at diagnosis died during follow-up. In univariate analysis, a symptomatic medu llary thyroid carcinoma was a strong predictor of an unfavourable outcome ( p < .00008), as were the preoperative calcitonin level (P = .007) and an el evated postoperative calcitonin level (P = .004). Among 30 histopathologica l criteria, only the presence of amyloid correlated with an unfavorable out come (P = .018). (C) 1999 by W.B. Saunders Company.