A case of an encapsulated mesenteric steatonecrosis mimicking a mesenteric tumour

A case report and a brief report of the literature

Abstract

Introduction: Mesenteric tumours comprise a heterogeneous group of lesions that may be neoplastic, inflammatory, or degenerative in origin. The wide variety of lesions and their rarity often hamper accurate diagnosis and decision-making. Moreover, some of them may represent an abdominal manifestation of systemic diseases or atypical infections that require medical treatment, and the wrong decision for “radical” surgery may have life-threatening consequences. 
Herein, we describe a case of encapsulated mesenteric fat necrosis (EFN) together with a brief review of the literature. 
Case report: A 67-year-old woman complained of sporadic, vague abdominal pain and mild abdominal discomfort. Her past medical history was cholecystectomy, hysterectomy due to a benign tumour, dyslipidemia, and arterial hypertension. There was no history of acute pancreatitis or trauma. She was referred to our clinic with a preliminary diagnosis of “mesenteric leiomyoma” based on an outpatient CT demonstrating a well-defined, rounded lesion with a firm, irregular periphery, calcifications, and central fat. There was contrast enhancement of the solid component in the late phase, a feature typical of fibrous tissue. Due to a suspicion of liposarcoma, the patient was scheduled for surgery. Laparoscopy revealed a pale, solid mass arising from the jejunal mesentery, which was easily excised.  Histopathological examination revealed encapsulated steatonecrosis. The patient had an uneventful recovery and was discharged home the next day.
Conclusion: Mesenteric tumours encompass cystic and solid lesions that may be benign or malignant. Accurate preoperative differential diagnosis is paramount for proper treatment planning. The surgery is indicated in almost all solid tumours and cystic lesions when they are symptomatic. The EFN could be observed due to its tendency toward spontaneous resolution. The most important differential diagnosis is liposarcoma, and surgery is indicated in case of diagnostic uncertainty.