Partial ablation of mediastinal parathyroid adenoma by angiography: Documentation with Tc-99m sestamibi scintigraphy

An 81-year-old man was diagnosed as having primary hyperparathyroidism and consequently had two adenomatous parathyroid glands removed. Postoperatively, the patient remained asymptomatic. Subsequent blood tests revealed hypercalcemia and increased parathormone (PTH) levels consistent with recurrent hyperparathyroidism. Tc-99m sestamibi imaging revealed a large parathyroid adenoma in the superior anterior mediastinum. Due to the patient's age, an angiographic embolization of the tumor was attempted. The thyrocervical trunk was selectively catheterized and a total of 30 cc of renographin 76 was administered. Although an extreme vascular blush was noted within the mediastinum, persisting for approximately 45 minutes, the PTH level remained elevated after the procedure, suggesting an unsuccessful ablation. A follow-up Tc-99m sestamibi scan 4 days after the angiographic intervention demonstrated persistent, but less intense, uptake with a central photopenic area indicating only partial embolization of the adenoma's blood supply, resulting in subsequent partial infarction of the central region. The patient underwent elective surgery and a well-circumscribed 8-g adenoma measuring 2.5 x 2.5 x 1.5 cm was removed. A large zone of infarction was noted, confirming the scintigraphic diagnosis.