MEDULLARY (SOLID) CARCINOMA OF THE THYROID—A CLINICOPATHOLOGIC ENTITY*

TLDR

Medullary carcinoma presents as a solid, non‑follicular tumor with stromal amyloid and frequent lymph node metastases, is of intermediate malignancy, and must be distinguished from anaplastic and papillary carcinomas. The study reports 21 cases (14 women, 7 men, ages 33–66, median 50). At surgery, 48 % had cervical lymph node metastases, distant metastases occurred in 8 patients (lungs, liver, bone), amyloid was present in all tumors, the disease course was usually chronic with 12 patients surviving 6–27 years, and 11 patients died (6 from the tumor) within 4 months to 27 years post‑surgery.

Abstract

Medullary carcinoma is characterized by a solid nonfollicular histologic pattern, the presence of amyloid in the stroma, and a high incidence of lymph node metastases. The tumor is clinically of an intermediate rather than a high grade of malignancy, despite its undifferentiated character. It is important to distinguish it from the highly malignant solid form of anaplastic carcinoma, and from papillary carcinoma, which is of a lower grade of malignancy. Twenty-one cases are reported. Fourteen patients were women and 7 were men; the ages ranged from 33 to 66 years with a median of 50 years. The regional cervical lymph nodes contained metastases at the time of initial surgery in 10 of 21 cases (48 per cent). Distant metastases occurred in 8 patients and were principally evident in the lungs, liver and bone. Amyloid, though of variable amount, was present in the stroma of all tumors of this series. The course of the disease was usually chronic; 12 patients survived six to twenty-seven years after the initial thyroid operation. Eleven patients died (6 because of neoplasm) four months to twenty-seven years after definitive surgical treatment.