Gastric cancer and adenomatous colorectal polyp concomitant with pyogenic liver abscess and bacteremia.

Synchronous gastric cancer and adenomatous colorectal polyp in patients with Klebsiella pneumoniae-induced pyogenic liver abscess (KP-PLA) and bacteremia is a rare presentation. A 58-year-old man with a 6-month history of diabetes mellitus (DM) presented with febrile sensation and dull abdominal pain in the right upper quadrant of the abdomen. Subsequent to laboratory test results and abdominal computed tomography findings, KP-PLA with bacteremia was diagnosed. After intravenous antibiotic administration, his symptoms improved, and upper endoscopy and colonoscopy were performed to evaluate the cause of KP-PLA. Biopsy specimens of the prepyloric anterior wall revealed a moderately differentiated adenocarcinoma. Endoscopic mucosal resection of the colon revealed high-grade dysplasia. Early gastric cancer (EGC) and adenomatous colorectal polyps with high-grade dysplasia concomitant with KP-PLA and bacteremia were diagnosed in our patient who had DM. Intravenous antibiotic treatment for KP-PLA, subtotal gastrectomy for EGC, and colonoscopic mucosal resection for the colon polyp were performed. After 25 days of hospitalization, subtotal gastrectomy with adjacent lymph node dissection was performed. Follow-up ultrasound imaging showed resolution of the abscess 5 weeks post-antibiotic treatment, as well as no tumor metastasis. Upper gastrointestinal endoscopy and colonoscopy should be performed to evaluate gastric cancer in patients with PLA or bacteremia, accompanied with DM or an immunocompromised condition.