Of a series of thyroid carcinomas, approximately 10% have been of the solid type. The histologic pattern of solid thyroid carcinoma is distinctive: I t is the only type that contains amyloid and it is unmixed with other types. The incidence in males and females is essentially equal. Solid carcinoma tends to metastasize to the cervical lymph nodes and the mediastinum. T h e diseases with which it is associated brings this type into special perspective among thyroid cancers. Its histologic pattern is not a guide to the prognosis. The treatment of choice is total thyroidectomy with resection of all regional metastases. Of 33 patients who were followed for five years or more after operation, 40% had no evidence of thyroid cancer a t the time of this study; 15% were living with disease; 36% had died of the disease and 9% had died of other causes. Institute. To the present time the study includes 562 microscopically proven carcinomas. Of these, 53 (9.4%) were of the solid variety.This type was chosen for the present discussion because it differs from all the other types in several respects:1. Solid carcinoma is not mixed with other types and its cellular morphology is distinctive; 2. T h e solid type is the only thyroid carcinoma that contains amyloid;3. From our experience, these tumors tend to spread through the lymphatics to the cervical lymph nodes and the mediastinum; 4. In contrast to the sex incidence of other types of thyroid carcinoma, which is two or more times higher in females, the incidence of solid carcinoma is essentially the same in males and females.In addition, the reports i n the medical literature of the association of solid carcinoma with pheochromocytoma, parathyroid adenoma, and Marfan's, Cushing's and the carcinoid syndromes brings this type into special perspective among cancers of the thyroid gland. A clinicopathologic analysis of these 53 cases, particularly with respect to these points, is presented.
MATERIALS AND METHODST h e hospital charts of the 53 patients bearing this type of thyroid cancer were reviewed. T h e thyroid glands of 41 patients were examined by the routine paraffin section technique and those of 12 patients by the whole organ subserial section technique. Sections of all primary and metastatic lesions were stained with hematoxylin and eosin for microscopic examination and special stains were employed for study of the amyloid. Crystal violet, Congo red, PAS with and without diastase digestion, alcian blue, mucicarmine and silver stains were employed routinely.
ANALYSIS OF CASESAge, sex and mcc: T h e ages of these 53 patients ranged from 15 to 82 years, the numbers of patients in the fourth, fifth, sixth and seventh decades of life being almost equal. Their median age at the onset of symptoms was 48 years and upon admission to this hos-706