Incarcerated sigmoid colon cancer in an inguinal hernia sac associated with an abdominal wall abscess: a case report

Background: An inguinal hernia is a common disease; however, a malignant tumor within the inguinal hernia sac is rare, and perforated colon cancer in the hernia sac is extremely rare. Case presentation: A 73-year-old man presented to our hospital with high fever and painful bulging of the lower abdomen. Computed tomography showed air-containing fluid in the abdominal wall, as well as localized wall thickness of the sigmoid colon in the left groin. An emergency operation revealed a huge subcutaneous abscess and a hard mass of the sigmoid colon within an indirect inguinal hernia sac. Sigmoidectomy and hernia repair using the Marcy method were performed. Lymph node dissection was performed through a transrectal abdominal incision. Histopathological examination of the resected specimen revealed moderately differentiated adenocarcinoma invading the serosal layer with lymph node metastasis. Conclusions: Incarcerated inguinal hernia with perforated colon cancer is rare; an emergent operation should accordingly be performed based on infection control, oncological principles, and secure hernia repair.