# Giant Extragastrointestinal Mesenteric Stromal Tumor: A Case Report and Literature Review of a Rare Entity With Nonspecific Symptoms

## TL;DR

This paper reports a rare case of a large abdominal tumor in a 52-year-old man, highlighting the challenges in diagnosing and treating this uncommon condition.

## Contribution

The novelty lies in documenting one of the largest extragastrointestinal stromal tumors reported in Mexico.

## Key findings

- A 52-year-old male had a successfully resected 22 x 14 x 21.8 cm extragastrointestinal stromal tumor.
- Histopathology showed CK117 positivity and high mitotic activity, consistent with EGIST characteristics.
- This case is the first documented EGIST at José Eleuterio González University Hospital.

## Abstract

Extragastrointestinal stromal tumors (EGISTs) are rare mesenchymal neoplasms with a low frequency compared to gastrointestinal stromal tumors (GISTs). EGISTs share histological and immunohistochemical features with GISTs but occur outside the gastrointestinal tract, commonly in the mesentery or omentum. We report the case of a 52-year-old male presenting with a large asymptomatic abdominal mass. Imaging revealed a semi-solid-cystic tumor measuring 22 x 14 x 21.8 cm. Exploratory laparotomy confirmed an EGIST originating in the mesentery, which was successfully resected without complications. Histopathology showed high mitotic activity, CK117 positivity, and areas of necrosis. Postoperative recovery was uneventful, and the patient remains under follow-up. To the best of our knowledge, this case represents the first documented EGIST at José Eleuterio González University Hospital and one of the largest reported in Mexico. EGISTs remain poorly understood, and early surgical intervention remains the cornerstone of treatment. Further research is essential to develop tailored guidelines for their management.