Primary Hyperparathyroidism with Extensive Brown Tumors and Multiple Fractures in a 20-Year-Old Woman

Abstract

A brown tumor is a benign fibrotic, erosive bony lesion caused by localized, rapid osteoclastic turnover, resulting from hyperparathyroidism. Although brown tumors are one of the most pathognomonic signs of primary hyperparathyroidism, they are rarely seen in clinical practice. In this report, we present a case of 20-year-old woman with recurrent fractures and bone pain. Plain digital radiographs of the affected bones revealed multiple erosive bone tumors, which were finally diagnosed as brown tumors associated with primary hyperparathyroidism due to a parathyroid adenoma. This case shows that multiple, and clinically severe form of brown tumors can even occur in young patients.

Keywords: Brown tumor; Hyperparathyroidism; Parathyroid neoplasms.

Fig. 1. Mongolian magnetic resonance imaging of the affected shoulder (A, T1 coronal; B, T2 coronal FS; C, T2 sagittal view) showed 5 cm-sized expansile tumorous lesion with heterogeneous signal intensity on right humerus metaphysis, with internal cystic change containing fluid level inside.

Fig. 2. Plain digital radiograph of the affected left wrist and hand (A), humerus (B), both tibia (C, left tibia; D, right tibia) and foot (E, left foot; F, right foot) revealed multiple bony osteolytic expansile lesions (arrows) with cortical thinning, diffuse osteoporosis and subperiosteal bone resorption, without definite evidence of pathological fractures in both tibia and fibula, metatarsal bones, left proximal ulna and humerus, left distal ulnar and 3rd metacarpal bone. These findings are thought to compatible with brown tumors of hyperparathyroidism and not like malignancy.

Fig. 3. Skull X-ray showed a granular "salt and pepper" appearance, which is thought to be a typical finding of primary hyperparathyroidism. It also showed enlargement of the sella turcica, which can be commonly seen in cases of pituitary tumors.

Fig. 4. Ultrasound of neck revealed several nodules which were thought to be parathyroid; well-defined hypoechoic nodules sized 0.85 cm, 0.75×0.74 cm, maximum size is 1.83 cm, and there was no other significant lymphadenopathy

Fig. 5. To further assess the parathyroid gland, technetium-99m (Tc-99m) sestamibi parathyroid scan was carried out, showing normal uptake pattern in both Tc-99m peretechnetate and focally increased residual uptake at the lower pole region of left thyroid lobe in the Tl-Tc pertechnetate subtraction image (A, early phase; B, delayed phase). This result showed "parathyroid adenoma" close to the left lower pole of left thyroid.

Fig. 6. Histopathological report showed features of parathyroid adenoma as above (H&E stain, A,×100; B, ×200). In figure (A) and (B), within the adenoma, tumor cells are arranged in cords and solid sheets. The tumor cells are mainly composed of chief cells, which have centrally placed hyperchromatic nuclei and pale eosinophilic cytoplasm.