Synchronous primary gallbladder squamous cell carcinoma and colon adenocarcinoma: A case report and literature review.

RATIONALE: Gallbladder (GB) malignancy is the most common biliary malignancy; however, squamous cell carcinoma of the gallbladder (GBSCC) is extremely rare. Synchronous primary GB and colon cancers are very rare, but they are still adenocarcinomas. PATIENT CONCERNS: The patient was a 68-year-old male who had symptoms of anemia and underwent a comprehensive examination. Irregular thickening of the GB wall and localized bowel wall thickening in the ascending colon were observed. DIAGNOSES: Colonoscopy revealed a large mass in the ascending colon, and adenocarcinoma was diagnosed by biopsy. INTERVENTIONS: Right hemicolectomy and extended cholecystectomy were implemented. OUTCOMES: The patient was diagnosed with synchronous primary pure GBSCC and colon adenocarcinoma. Anemia was found on the 10th postoperative day, and syncope occurred on the 12th day; computed tomography showed a gastroduodenal artery aneurysm, and covered stent insertion was attempted but failed. Consequently, intimal dissection and common hepatic artery embolization resulted, leading to hepatic failure, and the patient died on the 18th day. LESSONS: We report a case of synchronous primary pure GBSCC and colon adenocarcinoma. Synchronous primary GB and colon adenocarcinomas have rarely been reported. However, synchronous primary pure GBSCC and colon adenocarcinomas have not yet been reported in English literature. Here, we present a literature review on the pathogenesis of GBSCC and synchronous GB and colon cancer.