Parathyromatosis as cause of recurrent secondary hyperparathyroidism: a cytologic diagnosis.

Parathyromatosis is a rare cause of hyperparathyroidism. It can be divided into two types: primary and secondary. The pathologic lesion consists of multiple small nodules of hypercellular parathyroid tissue strewn in soft tissue (fat, skeletal muscle, fibrous tissue) of the neck. We present a case of parathyromatosis occurring in a patient with recurrent secondary hyperparathyroidism 4 yr after parathyroidectomy. The diagnosis was confirmed preoperatively by fine-needle aspiration of one of several neck masses.