Solitary Osteochondroma of the Calcaneum: A Rare Case Report

Solitary osteochondroma is the most common benign bone tumour, but its occurrence in the calcaneum is extremely rare, representing less than 1% of reported cases. Because of its location in a weight-bearing bone, calcaneal osteochondroma may mimic more common heel disorders and contribute to delayed diagnosis. This case is notable for the unusually large size of the lesion, its 20- year duration, and the requirement for a combined medial-lateral surgical approach, which is infrequently described in literature. A 39-year-old woman presented with a gradually enlarging, painful swelling on the plantar aspect of her left heel that progressively limited weight-bearing. Examination revealed a firm, immobile bony mass measuring approximately 5×5 cm. Diagnostic evaluation included radiographs, Computed Tomography (CT), and Magnetic Resonance Imaging (MRI). Imaging demonstrated a well-defined osseous outgrowth with corticomedullary continuity, while MRI showed stretching of the plantar fascia without abnormal signal and absence of a cartilage cap, supporting a benign osteochondroma and excluding malignant transformation. Routine biochemical investigations were within normal limits. The patient underwent complete excision of the lesion using a dual medial–lateral approach to achieve adequate exposure, with intraoperative fluoroscopy confirming total removal. Histopathology revealed mature trabecular bone with a cartilage cap and endochondral ossification, consistent with benign osteochondroma. Postoperative recovery was uneventful, and the patient regained full mobility with pain-free weight-bearing. This rare case highlights the importance of considering osteochondroma in the differential diagnosis of chronic heel swellings, the value of multimodal imaging for accurate characterisation, and the effectiveness of tailored surgical approaches for large calcaneal lesions.