Year: 2026 | Month: October | Volume: 13 | Issue: 10 | Pages: 1-9
DOI: https://doi.org/10.52403/ijrr.20261001
Bilateral Symmetric Atypical Lipomatous Tumor: A Case Report
Satria Pandu Persada Isma1, Istan Irmansyah Irsan1, Eviana Norahmawati2, Irma Darinafitri3, Dandy Drestanto Adiwignyo1, Mochamad Febryan Kevien Fadrijanto1
1Department of Orthopaedic and Traumatology, Faculty of Medicine, Universitas Brawijaya – Dr. Saiful Anwar General Hospital, Malang, Indonesia
2Department of Anatomical Pathology, Faculty of Medicine, Universitas Brawijaya – Dr. Saiful Anwar General Hospital, Malang, Indonesia
3Department of Radiology, Faculty of Medicine, Universitas Brawijaya – Dr. Saiful Anwar General Hospital, Malang, Indonesia
Corresponding Author: Satria Pandu Persada Isma
ABSTRACT
Introduction: Atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS) is the most common subtype of liposarcoma and may mimic benign lipomatous tumors because of its slow growth and nonspecific clinical presentation. Bilateral symmetrical involvement of the extremities is exceptionally rare and may complicate diagnosis.
Case Presentation: A 57-year-old woman presented with a two-year history of progressively enlarging bilateral thigh masses associated with persistent pain, predominantly on the right side. Physical examination revealed bilateral thigh enlargement, with circumferences of 60 cm on the right and 56 cm on the left. Plain radiography demonstrated soft tissue swelling without osseous involvement. Ultrasonography suggested a lipomatous lesion, while magnetic resonance imaging revealed extensive lipomatous masses with atypical features. Initial fine-needle aspiration biopsy favored an intramuscular lipoma. Because of the lesion size and atypical imaging findings, a multidisciplinary evaluation was performed, followed by core needle biopsy. Histopathological examination demonstrated atypical stromal cells within a lipomatous neoplasm, and immunohistochemical analysis showed positive MDM2 expression, confirming the diagnosis of bilateral atypical lipomatous tumor/well-differentiated liposarcoma.
Clinical Discussion: This case illustrates the diagnostic challenge of differentiating ALT/WDLPS from benign lipomatous tumors. Although imaging studies may provide valuable clues, definitive diagnosis requires histopathological and immunohistochemical evaluation. MDM2 positivity is particularly useful in distinguishing ALT/WDLPS from benign lipomatous lesions.
Conclusion: Bilateral symmetrical ALT/WDLPS of the thighs is an uncommon presentation that may initially resemble a benign lipomatous process. Comprehensive evaluation integrating clinical findings, imaging, histopathology, and MDM2 immunohistochemistry is essential for accurate diagnosis and appropriate management.
Keywords: atypical lipomatous tumor; bilateral thigh mass; lipomatous tumor; soft tissue sarcoma; well-differentiated liposarcoma.
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