Reoperative Parathyroidectomy: Overly Descended Superior Adenoma

Objectives To identify the importance of the ectopic, overly descended superior parathyroid adenoma variant and its prevalence in primary and reoperative parathyroid surgery and the implications for successful initial parathyroidectomy. Study Design Case series with planned data collection. Setting Tertiary endocrine surgery practice in an academic medical center. Subjects and Methods An analysis was undertaken of 561 consecutive patients undergoing parathyroid surgery in a tertiary endocrine surgery practice from March 2004 to April 2013. There were 270 patients who had curative primary or reoperative surgery for single-gland parathyroid adenomas during this time. Clinical records, imaging studies, operative reports, and pathology findings were evaluated, and cases from a subset of patients who had an ectopic, overly descended superior parathyroid adenoma were further analyzed. The prevalence of this entity in primary and revision surgeries was calculated. Results Among the 270 patients with single-gland parathyroid adenomas, there were 251 primary operations and 19 reoperative procedures referred from outside institutions. An ectopic, overly descended superior parathyroid adenoma was present in 23 (9.2%) primary cases and 4 (21.1%) reoperative cases. Conclusion An overly descended superior parathyroid adenoma is frequently encountered during primary parathyroid surgery. It is more than twice as common in reoperative parathyroidectomy, reflecting the propensity to be missed at the first exploration. Recognition and proper treatment of this entity at the initial operation will reduce the need for revision surgery.