A REVIEW OF 17 CASES OF CARCINOMA OF THE THYROID AND PHAEOCHROMOCYTOMA.

The salient features of 15 cases of carcinoma of the thyroid and phaeochromocytoma taken from the literature and two personal cases are reviewed. The significant points noted are the frequency with which the adrenal tumours were bilateral, the frequency with which a family history of phaeochromocytoma (six cases) and thyroid carcinoma (four cases) was present, and the frequency with which the type of thyroid tumour was medullary carcinoma. In four of the 15 published cases the thyroid tumour was described as being medullary. Two personal cases both had medullary carcinoma of the thyroid, and this was also the type of thyroid carcinoma present in five of the published cases in which the thyroid histology was personally reviewed, making a total of 11 medullary carcinomas out of 17 cases. At least one other tumour was probably medullary, judging by the histological description. It is suggested that the association between phaeochromocytoma and thyroid carcinoma is specifically with medullary carcinoma of the thyroid. Both personal cases showed multiple neural tumours; and because of this and the association with phaeochromocytoma the possible neural origin of medullary carcinoma of the thyroid is briefly discussed. The occurrence in a few cases of parathyroid tumours has raised the possibility that these cases are related to the multiple endocrine adenoma syndrome. The dissimilarity between the cases with medullary carcinoma of the thyroid and phaeochromocytoma and those cases with ademonas involving pituitary, parathyroid, adrenal cortex and pancreatic islets is stressed. The term ;medullary tumour syndrome' is suggested as a convenient non-committal name for this association of medullary carcinoma of the thyroid with tumours of the adrenal medulla.