Metastatic Parathyroid Hormone-Secreting Prostate Adenocarcinoma Mimicking Ectopic Parathyroid Adenoma Demonstrated on 99mTc-MIBI Image.

Tc-MIBI has long been used to localize hyperfunctioning parathyroid tissue in patients with hyperparathyroidism. This tracer can also concentrate in various neoplastic tissues including prostate adenocarcinoma. We herein report a case with parathyroid hormone-secreting metastatic prostate cancer mimicking an ectopic parathyroid adenoma on the Tc-MIBI scan. We conclude that metastatic prostate cancer should be included as one of the differential diagnoses when interpreting Tc-MIBI scan.