Function-sparing Compartmental Resection of a Giant Recurrent Well-differentiated Liposarcoma of the Thigh: A Case Report

Abstract

Introduction: Deep-seated adipocytic tumours of the limb larger than 10 cm and any lipomatous lesion recurring after a previous excision must be regarded as an atypical lipomatous tumour/well-differentiated liposarcoma (ALT/WDLPS) until molecular testing proves otherwise. Because these tumours virtually never metastasise unless they dedifferentiate, the therapeutic objective is to achieve durable local control at the lowest possible functional cost—a balance that becomes difficult when the tumour is enormous, multicompartmental, and ulcerated through the skin. Case Presentation: A 53-year-old woman was referred with a recurrent 30-cm mass of the left thigh, 15 years after excision of a lesion reported as an intramuscular lipoma. The tumour had fistulised through the posterolateral skin as an ulcerated, necrotic, fungating nodule. The first percutaneous core biopsy was non-contributory, whereas the second was falsely reassuring. Magnetic resonance imaging showed a fatty mass extending from the femoral head to the knee, displacing all four heads of the quadriceps and abutting, but not encasing, the vascular axes. After multidisciplinary discussion, an en bloc anterolateral and posterolateral compartmental resection was performed, including the overlying ulcerated skin and the periosteum facing the tumour, while sparing the femur, femoral neurovascular pedicle, sciatic nerve, and deep posterior muscle mass. The operating time was 150 minutes, and estimated blood loss was 100 mL. Pathology showed a 30-cm mature, well-differentiated adipocytic tumour with free surgical margins; MDM2 analysis was pending. Clinical Discussion: The case illustrates three recurring pitfalls: false reassurance from a benign biopsy in a giant lipomatous tumour, the diagnostic importance of recurrence after a supposedly benign excision, and the temptation to perform an amputation when a limb tumour becomes fungating. A compartment-oriented dissection enabled margin-negative resection without sacrificing bone, nerve, or vessel and preserved a weight-bearing limb with intact knee flexion and foot function despite loss of the extensor apparatus. Conclusion: Even at an advanced stage with skin fistulisation, a giant adipocytic tumour of the thigh can be resected with clear margins through a planned compartmental approach. Amputation is rarely necessary when the neurovascular axes remain free, and the functional benefit of preserving them is considerable.