Mesenteric Cystic Lymphangioma in an Adult

Abstract

Purpose: Introduction: Mesenteric cystic lymphangiomas (MCLs) are rare benign tumors, usually seen in children. Presented is an adult patient incidentally found to have an intra-abdominal cyst, diagnosed as MCL. Case Presentation: A 59-year-old male presented for evaluation of a renal cyst. Medical history was significant for bilateral cryptorchidism status post orchiopexy and BPH, with complaints of occasional abdominal cramping. Renal ultrasound showed a simple cyst in the upper pole of the right kidney, measuring 3.7 cm, with no evidence of septations or calcifications. Physical exam was unremarkable. CT abdomen/pelvis confirmed the presence of a renal cyst, but there was an incidentally found lesion in the bowel mesentery, described as a 5 cm complex mesenteric cyst. Due to concern for mucinous cystadenocarcinoma, the patient underwent exploratory laparotomy. The cyst was identified in the mesentery close to the duodenal-jejunal junction, with smaller cystic structures along the bowel wall. The cyst was removed. Gross pathology revealed a 4.2 cm by 3.5 cm by 2.0 cm mass with an irregular, lobulated surface. The cut surface was tan-yellow with thin walled cysts containing milky white fluid. Microscopic sections showed adipose tissue with multiple cystic structures, whose walls were composed of a smooth muscle layer, lined by flat cells (Figure 1), which stained positive for CD31, CD34, and D2-40. These findings were consistent with MCL. The patient did well post-operatively. Discussion: MCLs are rare in adults. The etiology of MCLs is unknown, but since most cases are seen during childhood, they are thought to be associated with developmental anomalies of the lymphatic system1. Histologically, lymphoid aggregates in the cyst wall distinguish MCLs from simple mesenteric cysts1. Clinically, most patients are asymptomatic or have vague abdominal complaints1. Diagnosis is ultimately based on histologic characteristics. Treatment is surgical.[682] Figure 1: Histology demonstrating smooth muscle and lymphocytic aggregates in the cyst wall.Conclusion: MCLs are a rare finding in the adult population, but should be kept in the differential of cystic intra-abdominal masses.