Multicentric brown tumors in primary hyperparathyroidism two years after surgery for giant cell granuloma of the nose

Introduction: So called brown tumors occur in approximately 3% of primary hyperparathyroidism. They are resorptive giant cell granulomas (GCG) of the bone, which are rare benign lesions comprising up to 5% of primary bone tumors in adults. Most arise in the metaphysical-epiphysical area, most commonly in distal femur, proximal tibia and distal radius. The most common symptom is pain. In 25% of cases locally aggressive behaviour is described. A small subset of this lesions develop metastases, usually to the lung. An even smaller subset may develop multicentric GCGs, to our knowledege about 48 cases have been reported in the literature.

Our patient: Here, we report a 26-year-old woman presenting with the disability to breathe through her left nostril. The study of a tissue sample obtained by biopsy suspected a giant cell granuloma. Consecutive radical surgery revealed a reparative giant cell granuloma with a maximum diameter of 6cm. 2 years after, our patient presented again with pain in both knees and the hip. Laboratory findings revealed an elevated calcium level (corrected according to Husdan) of 3.01 mmol/l, parathyroid hormone 102.7 pmol/l (normal range 1.6–6.9) and a decreased level for phosphate of 0.49 mmol/l (0.87–1.45). The alcaline phosphatase revealed concentrations around 440 U/l (35–104). Ultrasound and SESTA-Mibi-scintigraphy studies displayed a suspicious lesion, located at the inferior pole of the left thyroid lobe. Our patient underwent surgical removal of the parathyroid adenoma. Postoperatively the painful lesions in both knees diminished, CT scanning showed no proof of a recurrent facial giant cell tumor and our patient achieved persistent well-being 13 months after treatment.

Conclusion: Treatment of choice is the removal of the affected parathyroid gland and a wait-and-watch approach concerning the bone lesions, which then resolve in the majority of cases.