Technetium Tc 99m sestamibi sensitivity in oxyphil cell-dominant parathyroid adenomas

Objective A subset of parathyroid adenomas contains a relative overabundance of oxyphil cells that are capable of greater technetium Tc 99m sestamibi tracer uptake and retention than other cell types. We examined whether the presence of oxyphil cells augments the sensitivity of technetium Tc 99m sestamibi preoperative localization and whether the histologic findings of a lesion could be predicted based on the adenoma mass and serum calcium and parathyroid hormone levels. Design Retrospective, single-blinded comparison of technetium Tc 99m sensitivity rates, lesion mass, and preoperative serum calcium and parathyroid hormone values of patients with chief and mixed cell–dominant adenomas and those with oxyphil-dominant parathyroid adenomas. Setting Tertiary care university hospital. Patients Sixty-three patients diagnosed as having a parathyroid adenoma. Intervention All patients underwent resection of a parathyroid adenoma following a preoperative technetium Tc 99m sestamibi localization study and serum calcium and parathyroid hormone level analysis. Main Outcome Measure Technetium Tc 99m sensitivity rate. Results The overall technetium Tc 99m sestamibi sensitivity rate was 76.2%. The sensitivity within the chief and mixed cell–dominant (n = 52) and oxyphil cell–dominant groups (n = 11) were 71.2% and 100%, respectively ( P  = .04). There was no correlation between histologic findings of the lesion and its size or serum calcium and parathyroid hormone levels. Conclusions Oxyphil cell predominance within an adenoma augments technetium Tc 99m sestamibi scan sensitivity in a statistically significant manner. The use of technetium Tc 99m sestamibi preoperative localization may therefore be differentially greater in patients with these types of lesions.