A rare cause of acute abdominal distension presenting as a surgical emergency

A 16-year-old man, who was previously fit and well, presented as an emergency with a 2-day history of abdominal distension. Clinical examination showed a diffusely distended non-tender abdomen dull to percussion. Plain abdominal X-ray (Figure 1) showed no gas shadows on the right side of the abdomen, suggesting displacement of the intestine to the left side. Abdominal computed tomography scan (Figure 2) showed an enormous, multilocular fluid-filled mass lesion occupying most of the peritoneal cavity and measuring about 152 × 259 × 384 mm with no evidence of a solid component. The intestine was shifted to the left of the abdomen. There was evidence of compression of the retroperitoneal structures, in particular the renal vessels. Laparotomy and resection of this lesion was undertaken following mobilization of the lesion and division of the feeding vessels. Following excision of the lesion, a large defect in the mesentery of the ascending colon was found on the right side of the superior mesenteric vessels. The lesion contained haemoserous fluid (Figures 3 and 4). Histological examination of the lesion showed that the multicystic mass was partly lined by a single layer of flattened attenuated cells, fibrous tissue and histiocytes with foreign body-type giant cell reaction associated with cholesterol-like clefts. The fluid in the cyst lumen contained inflammatory cells, red blood cells, proteinaceous fluid and fibrin. The overall histological appearance, supported by immunohistochemistry, favoured the diagnosis of multilocular cystic lymphangioma. The patient made a good postoperative recovery and was discharged. He underwent surveillance computed tomography scan 6 months following surgery and a surveillance ultrasound scan 12 months following surgery and no evidence of recurrence was found. Further surveillance was planned with clinical review and abdominal ultrasound scans every 6 months for the next 2 years and annually thereafter.