Large Posterior Proximal Femur Osteochondroma Presenting in Adulthood - Diagnostic Challenges and Management Strategy: A Case Report.

Introduction: 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. Case Report: 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. Conclusion: 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.