The unequal distribution of parathyroid neoplasms in male patients.

There is a known lesser incidence of primary hyperparathyroidism and parathyroid neoplasms in male patients. Any difference in the anatomic distribution between males and females has not been documented. Review of our institutional experience with 125 pathologically confirmed parathyroid adenomas (119) or carcinomas (six) from 2000 through 2012 was conducted. The anatomic location was identified from operative records and the distributions between males and females were compared. Ninety-two females with parathyroid neoplasms had equal anatomic distributions between left and right sides and no significant difference between superior and inferior locations (P = 0.381). In marked contrast, tumors in 33 male patients had a significant predilection for the right side (67%, P = 0.016) and inferior position (85%, P = 0.033) and most notably the right inferior position (64%, P = 0.026). For the group as a whole, inferior adenomas were significantly more common (70%, P = 0.044). All patients had postoperative normalization of serum calcium levels. Late biochemical recurrence was noted in two patients. This is the first operatively confirmed delineation of the anatomic distributions of parathyroid neoplasms in separate sexes. Based on the unexpected findings of this study, we recommend the right inferior cervical region be explored first in males with suspected parathyroid tumors of indeterminate location.