MULTIPLE BROWN TUMORS IN UNSUSPECTED PRIMARY HYPERPARATHYROIDISM MIMICKING METASTATIC DISEASE ON RADIOGRAPH AND BONE-SCAN

A 33-year-old woman with left knee pain and a very destructive lesion in the proximal tibia by radiograph was referred for radionuclide bone scanning. Multiple 'hot spots' were seen throughout the skeleton on the Tc-99m HDP scan and the possibility of widespread malignancy was considered. Biopsy of the tibial lesion revealed a lesion with multiple giant cells compatible with a brown tumor. Serum calcium and parathormone levels revealed a hyperparathyroid state. Thyroid and thallium scans demonstrated normal technetium uptake in the thyroid gland and a focus of thallium uptake in the inferior aspect of the right lobe compatible with a parathyroid adenoma. Multiple other foci of thallium uptake were identified throughout the body corresponding to the lesions on the bone scan. Radiographs of some of these areas revealed that these lesions also were 'brown tumors.' The patient underwent subsequent excision of a right parathyroid adenoma.