Incidental Intramedullary Lipoma of the Proximal Femur Detected Following Trauma: A Case Report.

Introduction: Intramedullary lipomas are rare benign bone tumors, most commonly involving the calcaneus, with femoral involvement being uncommon. They are frequently asymptomatic and discovered incidentally during imaging for unrelated complaints, which may raise concern for more aggressive pathology. Case Report: A 64-year-old female presented following a mechanical fall with bilateral hip pain. Initial pelvic radiographs and computed tomography scans identified an elongated, non-aggressive lucent lesion in the proximal left femoral metaphysis. Subsequent magnetic resonance imaging (MRI) demonstrated homogeneous fat-signal characteristics with complete fat suppression and no aggressive features, consistent with an intramedullary lipoma. The lesion was entirely asymptomatic and unrelated to the presenting complaint. Conservative management with surveillance imaging was adopted. Conclusion: Characteristic MRI features allow confident diagnosis of intramedullary lipomas, avoiding unnecessary biopsy or surgical intervention. Recognition of these lesions is essential when they are incidentally detected following trauma.