Mesenteric fibromatosis. Case report.

Deep fibromatosis is a rare locally aggressive but not metastasizing proliferation. Intra-abdominal fibromatosis (IAF) occurs either in association with Gardner's syndrome or as a sporadic event and presents in most cases differential diagnostic problems with myofibroblastic or fibroblastic tumors, characterized by a more aggressive biological behaviour such as gastrointestinal stromal tumors (GISTs). In absence of loco-regional and/or distant metastasis differential diagnosis may be difficult and represents a topical issue, since it influences treatment choice. We describe the case of a patient with sporadic IAF in which the tumor locally involved the mesentery and presented no loco-regional and distant spread. On histology, some morphological features of the neoplasm were in common with a GIST. Definitive diagnosis was made, postoperatively, on the basis of immunohistochemical findings.