Primary adenosquamous carcinoma of the duodenum: a rare case report with review of literature

Adenosquamous carcinoma of the duodenum is a malignant tumor consisting of adenocarcinoma and components of squamous cell carcinoma, which is extremely rare. There are very few available case reports, and its clinicopathological features and treatment strategies remain difficult to elucidate. We describe a patient diagnosed with adenosquamous carcinoma of the duodenum and perform a literature review of reported cases. A 55-year-old male patient presented with a history of jaundice and fever with pruritus and clay-colored stools. Preoperative investigations suggested an elevation of transaminase, bilirubin, and tumor markers. Enhanced MRI of the abdomen suggested a mass in the descending portion of duodenum and a mass was visible in the pancreatic region, with no distant metastases. Endoscopy of the upper gastrointestinal tract revealed an infiltrative growth mass invading the duodenal papilla in the descending part of the duodenum. The patient underwent Whipple procedure. Histopathological and immunohistochemical examination confirmed adenosquamous carcinoma of the duodenum. Although R0 resection was performed, the cancer developed hepatic metastases 2 months after surgery and the patient died 4 months after surgery.