BACKGROUND: Segmental absence of intestinal musculature is a well described entity in premature infants. It presents with peritonitis, bowel perforation, and obstruction. The diagnosis is based on pathologic observation of absence of intestinal musculature. Researchers hypothesized that this entity is a result of a vascular accident during embryogenesis. However, segmental absence of intestinal musculature is no longer limited to the pediatric population. Recently, a few cases have been described in adults with and without significant vascular diseases. This change in the age of the affected population with segmental absence of intestinal musculature makes the understanding of the pathogenesis of this entity even more challenging.

CASE REPORT: Here, we report a case of segmental absence of intestinal musculature in a 64-year-old female. The patient presented to the emergency room with sudden onset of abdominal pain and signs of peritonitis. Abdominal computed tomography showed free air in the abdomen. Laparotomy was performed, and a perforation involving the descending colon was identified. Left hemicolectomy was performed. Pathologic examination of the resected colon showed segmental absence of intestinal musculature.

CONCLUSIONS: Although the pathologic diagnosis of segmental absence of intestinal musculature is straightforward, the assumption that this condition is limited to the pediatric population is a major player in overlooking this diagnosis in adults. Pathologists should be aware that this condition can present in adults and is segmental. Gross and microscopic examination of perforated intestine is required to reach the correct diagnosis. To our knowledge, twelve cases of this entity have been described in adults. Here we present the thirteenth case of segmental absence of intestinal musculature in an adult, and we discuss the clinical and pathologic findings of this entity as well as its pathogenesis.

Keywords: Congenital Abnormalities, Intestinal Perforation, Muscle Development