Peritoneal Carcinomatosis and Other Emergencies Not Related to Primary Colorectal Cancer

Synchronous peritoneal carcinomatosis occurs in approximately 5% of patients with colorectal cancer, whereas metachronous carcinomatosis is reported in 5–19% of cases. It requires medical and, in selected cases, surgical management that most of the times occurs in an emergency setting. Malignant bowel obstruction is a frequent complication of peritoneal carcinomatosis, with potentially severe complications and the need of a complex multidisciplinary management, ranging from medical therapy to interventional endoscopic or radiological procedures to emergency surgery. Careful evaluation of patients’ status, cancer disease history, and expected prognosis is required, if possible by a multidisciplinary team, to establish the optimal treatment. In this chapter, disease presentation, diagnosis, and treatment strategies for peritoneal carcinomatosis presenting in emergency setting are discussed in the light of the recent literature. Furthermore, colitis that may be associated with colorectal cancer or with chemotherapy regimens is discussed, including ischemic, neutropenic, and pseudomembranous colitis. Differential diagnosis of colitis is crucial to establish a prompt and appropriate treatment in these patients. The possibility of incidental diagnosis of colorectal cancer in patients treated for other emergency conditions is also discussed.