Marjolin ulcer with tibial bone invasion mimicking osteosarcoma: a case report

Introduction and importance: Marjolin ulcer is a rare and aggressive malignant transformation that arises in chronic wounds or scars, most commonly as squamous cell carcinoma. Advanced lesions may invade bone and mimic primary malignant bone tumors, creating diagnostic and therapeutic challenges. Extensive long-bone invasion is uncommon and may lead to confusion with osteosarcoma. Case presentation: A 27-year-old woman presented with a progressively enlarging ulcerated and fungating mass involving the left leg. She had sustained a burn injury to the same leg at the age of 3 years, followed by a chronic nonhealing ulcer persisting for approximately 24 years. Examination showed extensive soft-tissue involvement with exposed tibial bone. Hemoglobin level was 5 g/dL. Plain radiography and contrast-enhanced computed tomography revealed a large circumferential peritibial soft-tissue mass with extensive osteolytic destruction of the tibial midshaft, initially raising concern for osteosarcoma. Because of extensive soft-tissue and osseous involvement, the limb was considered unsalvageable, and a left above-knee amputation was performed. Histopathology demonstrated well-differentiated squamous cell carcinoma arising within the chronic burn ulcer with direct tibial invasion, confirming a Marjolin ulcer. Surgical margins were negative. The postoperative course was uncomplicated, with progressive stump healing, mobilization using walking aids, and referral for prosthetic rehabilitation. Clinical discussion: The distinctive feature of this case was extensive tibial invasion, producing radiological findings closely resembling a primary malignant bone tumor. Marjolin ulcer should remain in the differential diagnosis of destructive bone lesions beneath long-standing burn scars or chronic ulcers. Histopathology is essential for definitive diagnosis, and advanced local disease may require major amputation when adequate oncological clearance cannot be achieved with limb-preserving surgery. Conclusion: Marjolin ulcer should be suspected when a long-standing burn scar or chronic ulcer develops progressive enlargement, fungation, or underlying bone destruction. Early recognition, timely biopsy, complete excision with negative margins, and oncological surveillance are essential to prevent advanced skeletal invasion and to reduce major limb loss.