Subscapular Fossa Osteochondroma: A Case Report of an Anatomical Surgical Approach.

INTRODUCTION: Subscapular osteochondromas are rare lesions, and reports describing their management through the medial paravertebral longitudinal approach are scarce. This case highlights the surgical management of a giant symptomatic osteochondroma with suspected malignant transformation using a muscle-sparing approach that provided excellent functional recovery. Osteochondromas are the most common benign bone tumors and rarely involve the scapula. Although most remain asymptomatic, progressive pain, functional limitation, and cartilage cap thickening may raise suspicion of malignant transformation and justify surgical excision. CASE PRESENTATION: A 60-year-old woman was diagnosed with an incidental osteochondroma arising from the medial aspect of the subscapular fossa. After 10 years of conservative management, she developed progressive pain and functional limitation. Imaging demonstrated a 54 × 40 × 59 mm lesion with a cartilage cap thicker than 22 mm, raising suspicion of malignant transformation. The tumor was excised through Elhassan's medial paravertebral longitudinal approach. Histopathological examination confirmed a benign osteochondroma. At 1-year follow-up, the patient achieved excellent functional outcomes with a Constant score of 96, an ASES score of 98.3, an SSV of 100%, complete symptom resolution, and no evidence of recurrence. CONCLUSION: This case demonstrates that the medial paravertebral longitudinal approach provides safe exposure for giant osteochondromas of the subscapular fossa while minimizing soft-tissue disruption. Progressive symptoms and cartilage cap thickening should prompt evaluation for possible malignant transformation, even after years of apparently benign evolution.