# From benign appearance to malignant truth: a case report of mesenteric dedifferentiated liposarcoma with inflammatory myofibroblastic tumor-like features

## TL;DR

A rare case of aggressive mesenteric cancer initially mistaken for a benign tumor is reported, emphasizing the need for molecular testing.

## Contribution

The paper presents a novel case of DDLPS with IMT-like features, highlighting diagnostic challenges and the role of molecular analysis.

## Key findings

- The tumor showed morphological similarities to IMT but had distinct molecular features of DDLPS.
- MDM2 gene amplification was detected, confirming the aggressive nature of the tumor.
- The case underscores the importance of molecular pathology in distinguishing aggressive sarcomas from benign tumors.

## Abstract

Dedifferentiated liposarcoma (DDLPS) with inflammatory myofibroblastic tumor (IMT)-like features is a rare and diagnostically challenging variant of soft tissue sarcoma. We report the case of a 74-year-old man who presented with a mesenteric mass in 2022 and recurrent tumors in 2024. Tissue from both primary and recurrent tumors were submitted to our reference center for pathological reevaluation, with a suspicion of IMT being suspected. Although the tumors exhibited morphological characteristics consistent with those observed in IMT, they displayed distinctive histological, immunohistochemical and molecular features suggestive of DDLPS with IMT-like features, including amplification of the MDM2 gene. This report highlights the morphological spectrum of DDLPS, the diagnostic role of molecular pathology, and the importance of differentiating this aggressive neoplasm from benign entities such as IMT.