Segmental absence of intestinal musculature: An increasingly reported pathology

Background: Segmental absence of the intestinal musculature (SAIM) is a known but clinically rare entity involving partial or complete absence of the intestinal muscularis propria. Clinical presentation is consistent with peritonitis, and treatment involves an emergent laparotomy, bowel resection, and reanastamosis or possible ostomy creation. Diagnosis results from histopathologic evaluation of the resected intestinal specimen. Most of the publications are case reports. Methods: We retrospectively reviewed all surgical pathology files at a tertiary pediatric hospital from 2003 to 2010, identifying children who were noted to have absence of intestinal musculature on pathology. Patients meeting criteria were reviewed in detail, and data regarding clinical presentation, diagnostic testing, radiologic findings, treatment, and outcome were recorded. Results: Five patients were identified between 2003 and 2010 who received the diagnosis of SAIM. Patient age ranged from 1 to 99 days of life. All children were born preterm by cesarean section, had a mean birth weight of 828 ± 338 g, and were intubated after birth. Conclusions: The 5 patients presented are reviewed and contrasted with previous cases presented in the literature. Theories of pathogenesis and classification are discussed, and the cases are labeled as primary versus secondary SAIM.