Multiple Distal Femoral Osteochondromas Encasing Popliteal Neurovascular Bundle

Multiple hereditary exostosis syndrome is a rare diagnosis with approximately 1:50000 incidence prevailing in males. The exostoses or osteochondromas are benign but have the potential for malignant transformation in 1-5%. There is a strong genetic component, with exostosis (EXT) signaling pathways being an underlying cause. They can be symptomatic, with pain and functional deficit as the main complaints. We present a case of a 17-year-old male who presented with pain and anatomical deformity in his left lower femur. Magnetic resonance imaging revealed multiple osteochondromas compressing the popliteal neurovascular bundle. Excision of the osteochondromas was performed to decompress the neurovascular bundle in a multidisciplinary approach. Histological examination demonstrated no evidence of malignancy. Currently, there is no consensus for patients diagnosed with multiple osteochondromas regarding further investigation and/or screening for malignant transformation.