Endocrine Abstracts

Background and Aims: Primary Hyperparathyroidism is fairly common and the diagnosis is established by demonstrating raised blood parathormone levels in the presence of hypercalcemia. Sestamibi scan is an investigation used primarily to identify the offending gland which would help in surgery. The aim of this study was to assess the usefulness of sestamibi scan in Primary Hyperparathyroidism.

Method: Case notes for patients with Primary Hyperparathyroidism from 2000 to 2004 were reviewed. In total 71 patients were diagnosed with the condition. 53 patients had undergone sestamibi scan while only 49 of them underwent parathyroid operation. All the histology specimens were reviewed.

Results: Sestamibi scans for the 49 patients who underwent parathyroidectomy showed 33 were positive with 31 single and 2 multiple. 13 single, the 2 multiple and 7 scan negative were hyperplasias, while the rest were adenomas (18 scan positive and 9 scan negative). 17 patients with hyperplasia had 2 or more glands removed. 8 patients with adenomas and 3 patients with hyperplasia re-presented with hyperparathyroidism. On reviewing the histology of 48 patients, over 50% with the diagnosis of adenomas had to be corrected according to the recent classification. Out of the 27 adenomas, 14 were reclassified as hyperplasia (5 scan negative) and 1 had early features of malignancy (scan negative). 1 other patient with a diagnosis of carcinoma histologically had a negative scan.

Conclusion: This retrospective study shows the sestamibi scan is useful in identifying an offending gland. Both adenoma and hyperplasia had fairly equal positive and negative scans. Therefore the scan was unable to delineate a particular pathological cause except that multiple positive spots suggested hyperplasia. Patients with the diagnosis of carcinoma had a negative scan.