A 75 years old woman was diagnosed with primary hyperparathyroidism and serum calcium levels of 2.96 mmol/L (2.18–2.60 mmol/L). Parathyroid hormone was increased to 644.2 ng/L (18.4–80.1 ng/L). Sestamibi (methoxyisobutylisonitrile) scintigraphy detected a typical uptake on the left side of the neck (1) and another uncommonly high uptake in the right thorax (2). On computed tomography this lesion corresponded to a 5.3 cm large mass in the right fourth rib. Parathyroid surgery for an upper left parathyroid adenoma was performed together with a left hemithyroidectomy for multinodular goiter. Histopathological examination revealed parathyroid adenoma 4.0 cm in size, weighing 8.5 g. Postoperatively, both serum calcium and parathyroid hormone levels decreased to the normal range of 2.02. mmol/L, and 51.3 ng/L respectively. Biopsy of the right fourth rib identified a giant-cell brown tumor which is an osteolytic lesion that arises due to excessive osteoclast activity, leading to degeneration of bone and replacement with connective tissue. Until now, brown tumors on sestamibi scintigraphy have rarely been described. No specific treatment is necessary. Supplementation of vitamin D restores the bone defect in the course of time.
Translated from the original German by David Roseveare.
Figure.
a) MIBI scintigraphy: increased uptake by left parathyroid adenoma and right fourth rib;
b) Thoracic computed tomography: brown tumor of right fourth rib
Footnotes
Conflict of interest statement:
The authors declare that no conflict of interest exists.