Pituitary adenoma, primary parathyroid hyperplasia and papillary (non-medullary) thyroid carcinoma. A case of multiple endocrine neoplasia (MEN).

An acidophilic pituitary adenoma associated with primary nodular parathyroid hyperplasia and a small papillary thyroid carcinoma was discovered at the autopsy of a 44 year old female acromegalic. The thyroid carcinoma showed evidence of lymphatic spread. Several etiopathogenetic mechanisms for the non-medullary thyroid carcinomata associated with Multiple Endocrine Neoplasia (MEN) have been postulated, since the follicular epithelium of the thyroid does not belong to the neural ectoderm derivates unlike the C-cells of the thyroid, the adenohypophysis and probably the parathyroid glands. Apart from genetic influence, or coincidence, one has to rule out carcinogenic exposure or hormonal influence. Clinically speaking, one should always consider whether malignant thyroid disease coexists with hyperplastic or neoplastic parathyroid tissue.