Colon Cancer After Acute Diverticulitis Treatment
A 63-year-old female with no specific history visited the emergency room with complaints of dyspepsia and right lower quadrant pain that had begun 5 days prior. Her vital signs were a blood pressure of 111/75 mmHg, a pulse rate of 100 beats/min, a breathing rate of 24 breaths/min, and a body temperature of 36.3℃. The patient showed acute illness, and physical findings indicated right lower abdominal tenderness, but there was no rebound tenderness. The peripheral blood examination showed leucocytes had increased to 10,800/mm3 and C-reactive protein (CRP) to 10.7 mg/dL; liver function tests and electrolytes showed no abnormalities. No specific findings were observed on the plain abdominal X-ray. The abdominal CT findings showed a diverticulum of ~2 cm on the outside above the colonic wall of the ileocecal valve and ascending colon, which was accompanied by focal wall thickening, fat infiltration and inflammation of >5 cm (). Based on these findings, the patient was diagnosed with acute diverticulitis and was treated with intravenous antibiotics (ceftriaxone, metronidazole) for 10 days. She was discharged with improved symptoms. One month after discharge, the follow-up CT showed a cystic lesion of ~2.5 cm remaining in the area of diverticulitis; therefore, an abdominal CT was performed at the follow-up 3 months later to detect abscess formation. The size of the cystic lesion had increased to ~4 cm, and the focal wall thickening remained (). A biopsy was performed during colonoscopy for differentiation of a chronic abscess, a mucinous cyst and colon cancer. The ulcer lesion was covered with dirty exudates, and bleeding upon easy touch was evident in the proximal ascending colon and ileocecal valve (). The biopsy results confirmed an adenocarcinoma, moderately differentiated, with a carcinoembryonic antigen (CEA) level of 1.4 ng/mL. A right hemicolectomy was performed, and, based on the surgical specimen, the patient was finally diagnosed with a mucinous adenocarcinoma, moderately differentiated, at the T3N0M0 stage. The patient has been followed up without chemotherapy for 90 months; the cancer has not recurred to date.