Multiple Brown tumors in a Case of Primary Hyperparathyroidism with Pathological Fracture in Femur

Abstract

Introduction: Pathological fractures in long bones are commonly caused by simple bone cyst or Osteogenesis imperfecta in children and by metastatic tumors from primary carcinoma, multiple myeloma, osteoporosis, and bone tumors in adults. Hyperparathyroidism causing pathological fractures, though a well-known entity, is seen infrequently in clinical practice. The fractures occur in the expansile fibro-cystic bone lesions called as "Brown tumor." The reported case describes a patient with classical features of primary hyperparathyroidism (PHPT) having multiple lytic lesions in pelvis and bilateral femur with pathological fracture. It is being reported due to its rarity.

Case report: A 28-year-old young married lady presented with chronic dull aching pain in both thighs and difficulty in walking for 2 years. Examination revealed tenderness in both thighs, with antalgic gait. X-ray pelvis with both thighs showed multiple lytic lesions of variable size in both femora and pelvis. Blood investigations showed raised levels of serum calcium, with highly raised levels of serum parathyroid hormone (PTH). Contrast-enhanced computerized tomography (CT) scan of neck demonstrated parathyroid adenoma. The patient admitted for prophylactic nailing for right femur, developed a fracture while indoor and was managed by right proximal femoral nailing, followed by parathyroid adenoma excision. Follow-up showed dramatic clinical and radiological improvement with good healing of fracture. Lytic lesions healed gradually and blood parameters returned to normal. The patient remains asymptomatic at 2 years follow-up.

Conclusion: Advanced case of symptomatic PHPT affecting bones is rare and it should be considered as a differential diagnosis in cases of a solitary and or multiple osteolytic lesions. Serum calcium and PTH level estimation at an early stage prevents missing the diagnosis and progression of disease. Early diagnosis and appropriate treatment help in rapid clinical improvement with almost total reversal of bony changes, thus avoiding devastating complications.

Keywords: Hyperparathyroidism; brown tumor; femur; osteitis fibrosa cystica; pathological fracture.

Figure 1

(a) Lytic lesions in both pubic rami, both ilium and right upper femur. (b) Shows progression of lytic lesions especially in the right proximal femur.

Figure 2

(a) Multiple lytic lesions in shaft of right femur with thinned out cortex. (b) Multiple lytic lesions in upper 2/3rd shaft and greater trochanter of the left femur. (c) Pathological fracture through the lytic lesion of the right femur.

Figure 3

(a and b) Axial and coronal cuts on magnetic resonance imaging of both thighs show lytic lesions in both femur.

Figure 4

(a): Immediate postop X-ray showing stabilization of right femur with long Proximal femur nail. (b) AP and lateral view X-rays at 1-year follow-up showing good union with cortical continuity and acceptable alignment of bone with PFN.

Figure 5

1-year follow-up X-ray of the left femur.

Figure 6

Histopathological section showing well encapsulated parathyroid tumor having tumor cells in sheets with adequate eosinophilic granular cytoplasm and centrally placed nuclei with mild nuclear atypia. No malignant cells, capsular, or vascular invasion seen.