Histological diagnosis of carcinoma of the parathyroid gland

During the period 1950-81, 678 cases of primary hyperparathyroidism were surgically treated at University College Hospital, London. The causes were a single adenoma in 575, two adenomas in 25, carcinoma in 20 (two of which had coexistent adenomas), chief cell hyperplasia in 56, and water clear cell hyperplasia in two. Histological diagnosis is not difficult except in some cases of carcinoma and in a few in which differentiation between recurrent hyperplasia and recurrent carcinoma is exceptionally difficult. In this paper we review all the cases of primary carcinoma of the parathyroid seen during this period to define those pathological features of value in the diagnosis.