Mesenteric, omental, and retroperitoneal cysts in children: a clinical study of 22 cases.

Cystic lesions of the mesentery, omentum, and retroperitoneum are rare; from 1956 to 1990, 22 patients had operative treatment for such lesions at our institution. They ranged in age from 1 month to 14 years; 75% were younger than 5 years. All had either an acute abdomen or, more commonly, a silent abdominal mass. In all cases, the histologic diagnosis was lymphangioma. Abdominal ultrasonography was done in all cases after 1977 except for two patients who had an acute abdomen requiring emergency exploration. A cystic abdominal mass was diagnosed in 94% of these cases, but the correct diagnosis of lymphangioma was made prior to surgery in only 24%. Mesenteric cysts are most common in the small bowel mesentery. Omental cysts usually occur singly and are easily resected, but multiple cysts predominate in the mesentery and retroperitoneum. Complete resection was accomplished in 82% of our cases. Two patients required partial bowel resection, and four had partial excision with marsupialization of the cysts. With a mean follow-up of 23 months, we have had three recurrences, but none necessitated reexploration. Extra-abdominal lesions, mainly cutaneous lymphangiomas, developed in two cases. Prognosis is good after surgical excision, but long-term follow-up is advisable because of the possibility of recurrence, even during adulthood.