Mediastinal, retroperitoneal, and subcutaneous emphysema due tosigmoid colon penetration: A case report and literature review

tINTRODUCTION: Mediastinal and subcutaneous emphysema usually result from spontaneous ruptureof the alveolar wall. We present an extremely rare case of massive mediastinal, retroperitoneal, andsubcutaneous emphysema due to the penetration of the colon into the mesentery.PRESENTATION OF CASE: A 57-year-old man presented to our institution with a history of chest pain.The patient’s medical history included malignant rheumatoid arthritis during the use of steroids andan immunosuppressive agent. The patient had no signs of peritoneal irritation or abdominal pain. Achest radiography revealed subcutaneous emphysema of the neck, mediastinal emphysema, as wellas subdiaphragmatic free air. Computed tomography showed extensive retroperitoneal, mediastinal,and mesenteric emphysema of the sigmoid colon without pneumothorax. Diagnostic laparoscopy wasperformed and revealed perforation into the sigmoid mesentery. Segmental resection of the sigmoidcolon and end-colostomy were performed. The diverticulum was communicating with the outside of themesentery via the mesentery. The mediastinal emphysema disappeared a few days after the surgery.DISCUSSION: Colonic perforation generally results in free perforation. Colonic gas may spread via variousanatomical pathways when perforation of the colon occurs in the retroperitoneum; thus, diverse atypicalclinical symptoms may be present. Signs of peritoneal irritation can be hidden in cases of retroperi-toneal colonic perforation. The atypical manifestation of a retroperitoneal colonic perforation can causedifficulties in making a diagnosis.CONCLUSIONS: Massive mediastinal and retroperitoneum emphysema are rare signs of colonic perfora-tion. Emergency laparotomy should be considered in colonic penetration of the diverticulitis where theemphysema expands to the mediastinum extensively.