Osteochondroma of the Left Proximal Tibia in a 12-Year-Old Male: A Detailed Case Report

Background: Osteochondroma is a common benign bone tumour in children and adolescents and usually arises from the metaphysis of long bones. Case presentation: A 12-year-old boy presented with an eight-month history of a progressively enlarging swelling over the proximal left leg associated with mild discomfort during prolonged walking, running and squatting. Examination revealed a hard, non-tender swelling measuring approximately 4.5 × 3 cm. Radiographs demonstrated a sessile bony outgrowth from the proximal tibial metaphysis with continuity of the cortex and medullary cavity with the parent bone. Magnetic resonance imaging showed a lesion measuring approximately 2.4 × 3.8 × 6.2 cm with a cartilage cap measuring 3.5–4.5 mm and no compression of the popliteal vessels or tibial nerve. Complete surgical excision was performed, and histopathological examination confirmed benign osteochondroma without malignant transformation. At six months, the patient remained asymptomatic with no clinical or radiological evidence of recurrence. Conclusion: Surgical excision of this symptomatic proximal tibial osteochondroma was associated with a satisfactory short-term functional and cosmetic outcome.