DOI: https://doi.org/10.36347/sasjs.2026.v12i11.003

Pages: 910-915

Background: Lipomas are the most common benign soft-tissue tumors. However, giant deep-seated lipomatous tumors of the extremities are uncommon and may raise concern for atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL), particularly when they are large and recurrent. We report a rare case of a giant recurrent lipomatous tumor of the thigh with a 46-year clinical course. Case Presentation: A 70-year-old man presented with a progressively enlarging mass of the right thigh causing heaviness and walking discomfort. He had previously undergone two surgical excisions at the same site in 1980 and 2000. Magnetic resonance imaging revealed a large deep-seated lipomatous lesion of the right thigh measuring 34 × 19 × 20 cm, with internal septa and heterogeneous post-contrast enhancement, displacing adjacent muscles without vascular or bony invasion. Complete surgical excision was performed through a curvilinear incision. The specimen measured 35 × 15 × 13 cm and weighed more than 5 kg. Histopathological examination showed a mature adipocytic proliferation with fibrous remodeling, dystrophic calcifications, and focal lipoblast-like cells with nuclear atypia. Immunohistochemistry was negative for MDM2 expression, supporting a benign lipomatous lesion rather than ALT/WDL. The postoperative course was uneventful. At 2-month follow-up, the patient had satisfactory healing and no clinical evidence of early local recurrence. Conclusion: This case highlights the diagnostic difficulty of giant recurrent deep-seated lipomatous tumors of the thigh. Magnetic resonance imaging is essential for preoperative assessment, while complete surgical excision and careful histopathological evaluation remain central to management. The prolonged interval between recurrences also supports long-term follow-up in recurrent deep lipomatous lesions.