WTP2.3 Incidence of intrathyroid parathyroid adenoma - last 9 years in a teaching hospital

Abstract

Abstract Aim The incidence of intrathyroid parathyroid adenoma (iTPA) is estimated to be 0.7-5.7% of hyperparathyroidism cases. Thyroid lobectomies may be performed when an adenoma cannot be clearly identified and isolated. We aimed to review the incidence of iTPA and outcomes after surgery within our practice. Methods We retrospectively reviewed consecutive parathyroidectomies performed by two experienced upper gastrointestinal surgeons (VS and PT) in a teaching hospital between April 2013 and December 2022. Preoperative radiological imaging was reviewed, and cases of iTPAs were diagnosed intraoperatively and on histopathology. These were further evaluated to review the outcomes after surgery. Results Total of 211 parathyroidectomy surgeries were performed, 11 (5.2%) of which were found to be iTPAs. These were confirmed on histopathology. Median age of patient cohort was 57±13 years. Patients were predominantly female (n=10, 90.9%). None underwent previous neck exploration. There was radiological (SPECT and Ultrasound) suspicion of iTPAs in 3 (1.4%) cases; peri-operative decision was made to explore for iTPA in the remaining 8 cases. 9/11 (81.8%) patients had hemithyroidectomy performed; in the remaining two cases, adenoma was successfully isolated from thyroid tissue and resected. Preoperative methylene blue infusion was utilised in all cases, of which uptake was evident in 8 (72.7%) cases. Calcium normalised in all patients postoperatively and none required further neck exploration. Conclusion Our 9-year series of parathyroid surgery revealed 5.2% incidence of iTPA, the majority of which was diagnosed intraoperatively. Diagnosis of iTPA should be considered if there is suspicion on radiological imaging and where no obvious adenoma is identified after full neck exploration.