Sigmoido-Cecal Fistula: A Rare Case of Complicated Recurrent Diverticulitis and a Review of the Literature

Bowel Obstruction as the Initial Presentation of Urothelial Carcinoma

Bowel obstructions are one of the main causes of hospital admissions for acute abdominal pain. In addition, bladder cancer is one of the most common cancers in the world. This said, bowel obstruction and bladder cancer are very frequent diseases but the same cannot be said about the association between these two pathologies. We report a unique case of an 80-year-old patient admitted to the emergency room with a bowel obstruction caused by a urothelial carcinoma with adrenal metastasis. The patient underwent an urgent laparotomy, and intraoperative inspection of the peritoneal cavity confirmed a large tumorous mass suspected of gastrointestinal etiology. The mass infiltrated the ileum and sigmoid colon and was apparently in contact with the bladder wall. An en-bloc resection of the lesion was performed. An R0 excison was not possible and fragments of the lesion were excised from the bladder wall for separate analysis. Histopathological examination of the resected specimen described a high-grade, undifferentiated urothelial carcinoma that originated in the bladder and invaded the ileum and sigmoid colon. The presence of an invasive urothelial carcinoma presenting with bowel obstruction represents an unexpected diagnosis and, although rare, the surgeon must be aware of this possibility. This case should serve as a reminder that a broad differential diagnosis should be considered when investigating an abdominal tumor.

Metastatic bladder cancer forming a sigmoidorectal fistula after enfortumab vedotin therapy: a case report

We report the case of a 68-year-old man who developed a sigmoidorectal fistula after marked response to enfortumab vedotin for advanced bladder cancer. The patient had undergone radical cystectomy with ileal conduit after neoadjuvant chemotherapy. Six months after surgery, local recurrence in the pelvic cavity and multiple lung metastases were found, and the patient was administered pembrolizumab as second-line therapy. Due to worsening local recurrence and suspected invasion of the sigmoid colon and rectum, enfortumab vedotin was initiated as third-line therapy and comprehensive genomic profiling was simultaneously performed. Enfortumab vedotin was remarkably effective, the lung metastases disappeared, and the local recurrent lesion shrank in volume although a sigmoidorectal fistula was found to form through the tumor cavity. Immunohistochemical analysis of the tumor specimens exhibited increased nectin-4 expression. This rare case of metastatic bladder cancer with sigmoidorectal fistula associated with effective enfortumab vedotin therapy suggests that nectin-4 expression and comprehensive genomic profiling might be useful in predicting treatment response to enfortumab vedotin.

Complicated Diverticulitis and Pelvic Radiation Leading to Colonic Stricture, Colorectal Fistula, and Anal Stenosis

The purpose of this case is to highlight a rare case of sigmoid colon-to-rectum fistula. A 66-year-old man with a history of pelvic radiation and diverticulosis presented to the emergency department with a 3-week history of abdominal pain and watery diarrhea. Computed tomography (CT) imaging was significant for a sigmoid-to-rectum fistula with sigmoid stricture. The patient underwent a laparoscopic colectomy with end colostomy. Pathology revealed perforated diverticulitis. To date, there have been no cases reported in literature describing sigmoid-to-rectum fistula. In conclusion, it is important to consider the development of complex diverticular disease in patients with history of pelvic radiation.