Secondary Neoplasm of the Thyroid Presenting as a Goitre.

Secondary neoplasm is a very rare finding in a goitre despite the numerous reports of metastatic deposits in the thyroid gland at necropsy. Eleven cases are reported of such deposits presenting clinically as a thyroid nodule, the sites of origin including a meningioma and an unusual carcinoma of the skin. Some of the factors, including pre-existent degenerative processes, believed to determine the incidence of secondary neoplasm in the thyroid, are discussed together with the problems of establishing the diagnosis.