Sigmoid colon cancer presenting as a large abdominal mass accompanied by abscess and rupture: a case report and literature review.

Introduction and Importance: Colon cancer presenting as a large abdominal mass accompanied by abscess and rupture is rare and prone to be misdiagnosed and delayed. In addition, the treatment plan is not clear when combined with abdominal wall metastasis. Case Presentation: A 79-year-old woman presented with a large abdominal mass accompanied by abscess and rupture. It was misdiagnosed as a soft tissue infection in a local hospital, and after a comprehensive examination, it was diagnosed as sigmoid colon cancer with abdominal wall metastasis and abscess formation. The patient underwent a one-stage surgery, including en bloc resection of the tumor and invaded abdominal wall, as well as autologous tissue abdominal wall reconstruction, with a good clinical prognosis. Clinical Discussion: For the diagnosis of large abdominal masses, abdominal CT, and pus culture are more valuable than ultrasound. For colon cancer with abdominal wall metastasis, one-stage surgery to completely remove the tumor and full-thickness of the abdominal wall, and the use of autologous tissue abdominal wall reconstruction technology to repair defects is feasible. Conclusion: This case highlights the importance of using colon cancer as one of the differential diagnoses for the diagnosis for large abdominal mass accompanied by abscess and rupture in elderly patients, as well as the possibility of one-stage surgical resection of the tumor and invasion of the abdominal wall and reconstruction of the abdominal wall with autologous tissue when there is abdominal wall metastasis.