A case of multiple skeletal lesions of brown tumors, mimicking carcinoma metastases

Abstract

Brown tumor is not a true tumor, being an unusual reactive lesion in association with primary or secondary hyperparathyroidism. We report a 23-year-old woman, who initially presented with lower back pain caused by ureterolithiasis. The initial diagnosis of brown tumor was delayed, but later pain in her leg worsened and a sacral lesion was incidentally discovered on lumbar magnetic resonance imaging (MRI); multiple destructive bone lesions were then found radiologically. The radiological features of the multiple bone lesions, which mimicked multiple metastatic tumors, seemed to be those of the terminal stage of malignancy. However, pathological examination and abnormal laboratory data showing elevated serum calcium, alkaline phosphatase, and parathyroid hormone and low serum phosphate confirmed the diagnosis of brown tumor. Adenoma in the parathyroid gland was confirmed and surgically resected. The clinical symptoms of bone pain, and abnormal radiological findings and laboratory data were resolved 6 months after surgery. Synthetic analysis of the clinical, radiological, and laboratory findings was necessary for the definite diagnosis of brown tumor.

Brown tumors of the anterior skull base as the initial manifestation of true normocalcemic primary hyperparathyroidism: report of three cases and review of the literature

“…Brown tumor represents localized accumulation of fibrous tissue and giant cells, which can replace bone and may even produce osseous expansion and subsequently undergo necrosis and liquefaction, producing cysts as a result of intraosseous bleeding and tissue degeneration (1,5,(9)(10)(11)(12).…”

“…Approximately 15% to 20% of patients have a pathological process (hyperplasia) involving all four parathyroid glands (9,12,21,25).…”

“…In fact, brown tumor has a minimal affinity for skull base bones. Multiple bone involvements are exceedingly rare in primary HPT and may be mistaken for clinical diagnosis of metastatic lesions (3,9,11,18,26).…”

“…Brown tumor is a benign reactive destructive process of bone that occurs in patients with either primary or secondary hyperparathyroidism (HPT) (1,2,9,10,12). The lesion appears to be relatively rare in the skull base and orbital region (1,10,12).…”

“…It is generally classified into primary, secondary, and tertiary depending on its etiology (1,12,21). Primary HPT is usually due to a single parathyroid adenoma (5,9,12,21). The most common presentation of primary HPT is hypercalcemia which is asymptomatic (10,11).…”