Liposarcoma of Thigh: A Case Report

Soft-tissue tumours of the extremities often present with a deceptively benign clinical course, leading to delayed diagnoses in cases of malignancy. Among them, Well-Differentiated Liposarcoma (WDLS) is one of the most prevalent lipogenic sarcomas, yet its resemblance to indolent lesions such as lipomas, fibromas, or chronic haematomas can obscure its true nature. The present case report details a 52-year-old man presenting with a slow-growing, painless thigh mass initially presumed to be benign. Advanced imaging revealed features suggestive of a lipomatous tumour with atypical septations. Subsequent core biopsy and immunohistochemistry confirmed the diagnosis of WDLS. The patient underwent successful Wide Local Excision (WLE) with negative margins and remains recurrence-free at 18 months. The case underscores the diagnostic dilemma faced in primary care and surgical settings, where limited access to Magnetic Resonance Imaging (MRI) or biopsy may delay definitive treatment. Differentiation between benign and malignant adipocytic tumours hinges on subtle radiologic cues such as thickened septa and non-lipomatous nodules, as well as confirmatory molecular markers like Murine Double Minute 2 (MDM2) and Cyclin-Dependent Kinase 4 (CDK4). As highlighted by this case and supported by recent World Health Organisation (WHO) updates, a structured diagnostic algorithm combining clinical suspicion, imaging, and histopathology is vital. Mislabeling malignant lesions as benign risks inadequate resection, recurrence, and suboptimal outcomes. Early recognition and referral remain critical to optimising management and preserving limb function. The present report serves as a practical reminder to maintain a high index of suspicion when evaluating persistent extremity swellings, even in the absence of alarming features.