Volume :

3

Issue :

2

Abstract :

Mesenteric Fibromatosis is a locally aggressive myofibroblastic proliferation of the mesentery and adjacent tissues that lack the capacity to metastasize. Mesenteric Fibromatosis (MF) and gastrointestinal stromal tumors (GISTs) are distinct lesions, but they are often confused with each other. Although rare, it is the most common primary tumor of the mesentery and can develop at any age. Here, we describe a rare case of primary Intra-abdominal Fibromatosis involving the mesentery and transverse colon in a 50 year old female which clinically, grossly and histologically mimicked gastrointestinal stromal tumor (GIST). Immunohistochemistry was done which revealed that the tumor mass showed focal coarse granular positivity for c-kit (CD117), while negative for CD34, DOG, desmin, S-100 and SMA. Furthermore, tumor mass showed over expression of β-catenin. This confirmed the diagnosis of localized mesenteric fibromatosis. Correct identification of both the entities (GIST & Fibromatosis) is of utmost importance as they differ vastly in therapeutic and prognostic considerations.