Subserous lymphangioma of the sigmoid colon: an uncommon cause of acute abdomen in pediatric patients

Abstract

Lymphangioma is a rare, benign lesion derived from a malformation of the lymphatic system, which is more frequently found in the head, neck, and axilla. However, it may be present anywhere in the body, and the diagnosis involves adults as children with some distinct clinical features among them. In pediatric patients, abdominal cystic lymphangioma occurs mostly in the mesentery presenting abdominal pain, intestinal obstruction, or, more rarely, hemorrhage. The authors report the case of a child with a short-course history of fever, abdominal pain, and constipation. The physical examination disclosed the presence of an abdominal mass and signs of peritoneal irritation. Imaging was consistent with a cystic lesion compressing the sigmoid colon and laterally displacing the remaining loops. Exploratory laparotomy was undertaken, and a sigmoidectomy, followed by Hartman's colostomy, was performed. Histological examination revealed the nature of the lesion as a cystic lymphangioma. The authors highlight the clinical features of this entity and call attention to this disease in the differential diagnosis of acute abdomen or abdominal pain, mainly in pediatric patients.

Keywords: Abdomen, Acute, Surgical Procedure, Operative; Colon, Sigmoid; Lymphangioma, Cystic.

Figure 1. Multidetector computed tomography of the abdomen. A - Coronal reformation showing a cystic lesion over the urinary bladder and displacing mesenteric vessels to the right; B - Sagittal reformation depicting tiny parietal calcifications on the tumor wall; C and D - Axial images showing an abdominal cystic lesion displacing intestinal loops and mesenteric vessels in C, and thin septa within the lesion in D.

Figure 2. Gross findings of the surgical specimen. A - Note a lobulated mass in the mesenteric face of the sigmoid; B - Formalin-fixed of the longitudinal section of the sigmoid colon showing a multiloculated cystic mass within the adipose mesenteric tissue. The intestine wall is preserved without invasion.

Figure 3. Photomicrography of the cystic lesion. A - Presence of multiple cystic lesions within the subserous layer of the sigmoid segment filled by amorphous and proteinaceous fluid (H&E, 25X); B - The cysts are lined by a flat unilayered cells without atypia, similar to endothelium. Note a lymphoid aggregate in the cyst wall (H&E, 100X); C - Ulcerative area with mixed inflammatory infiltrate, granulation tissue, and fibrin plug (H&E, 100X); D - Positive immunohistochemical reaction for CD-31 in the cystic endothelial lining and in the small vessels of the wall (200X).