Intraperitoneal Dedifferentiated Liposarcoma: Unveiling a Rare Diagnosis in Peritoneal Fluid Cytology - A Case Report with Literature Review

Introduction: Sarcomas presenting as malignant effusions are rare, and diagnosing them on fluid cytology requires expertise and clinicoradiological correlation as cells undergo morphological changes, mimicking carcinoma or mesothelioma. Case Presentation: We present a case of a 70-year-old man with abdominal distention and pain, initially suggestive of carcinoma on peritoneal fluid cytology. However, subsequent analysis with immunohistochemistry on the cell block revealed diffuse nuclear positivity for MDM2, leading to the diagnosis of dedifferentiated liposarcoma. Conclusion: The cytological diagnosis of dedifferentiated liposarcoma is challenging and requires a high index of suspicion, with clinicoradiological correlation. Utilizing immunohistochemistry on cell block samples enhances diagnostic accuracy and guides appropriate patient management.