Large Posterior Proximal Femur Osteochondroma Presenting in Adulthood - Diagnostic Challenges and Management...

Osteochondroma is the most common benign bone tumor and is usually asymptomatic. Neurovascular complications are uncommon, particularly in lesions involving the proximal femur. Sciatic nerve involvement secondary to a posterior proximal femoral osteochondroma is rare and may present with atypical symptoms, leading to delayed diagnosis.

A 35-year-old male presented with a 3-year history of progressive right gluteal pain and discomfort associated with intermittent numbness of the right lower limb, which was aggravated by prolonged sitting. Clinical examination revealed a deep-seated bony swelling in the gluteal region with sensory deficits in the superficial and deep peroneal nerve distributions. Radiographs and magnetic resonance imaging demonstrated a large posteriorly projecting proximal femoral osteochondroma measuring 4.8 × 5.5 × 7.4 cm with corticomedullary continuity and posteromedial displacement of the sciatic nerve. The lesion was excised completely through a posterior approach with careful identification and protection of the sciatic nerve. Histopathological examination confirmed a benign osteochondroma. Postoperatively, the patient experienced complete resolution of neurological symptoms and significant improvement in gluteal pain.

Posterior proximal femoral osteochondromas can remain clinically silent for decades before presenting with symptoms related to sciatic nerve irritation. The presence of proximal femoral remodeling in this case suggested a longstanding lesion likely present since skeletal growth. Advanced imaging is essential for diagnosis and surgical planning. Complete excision provides excellent symptomatic relief and prevents further neurological compromise.