Cecal Perforation Presenting as Apparent Peritoneal Carcinomatosis: Distinguishing Acute Peritonitis From Malignant Mimicry.

Cecal perforation is a rare but life-threatening surgical emergency that may present with radiologic and intraoperative findings highly suggestive of peritoneal carcinomatosis. This overlap may create substantial diagnostic uncertainty, particularly in patients with systemic symptoms such as weight loss, anemia, and ascites. We report the case of a 39-year-old male patient who presented with sepsis, abdominal pain, and computed tomography (CT) findings concerning for carcinomatosis, including ascites and mesenteric nodularity. Exploratory laparotomy revealed diffuse fibrinous exudates and peritoneal studding highly suspicious for malignant dissemination. However, histopathologic evaluation of peritoneal, mesenteric, omental, and cecectomy specimens demonstrated only acute and chronic inflammation, focal fat necrosis, abscess formation, granulation tissue, and reactive mesothelial changes, with no evidence of dysplasia or malignancy. This case highlights the diagnostic challenge posed by inflammatory mimics of carcinomatosis and underscores the essential role of histopathology in guiding management in complex abdominal emergencies.