Gastric adenocarcinoma at stage IV with complete remission after neoadjuvant therapy concurrent with adenosquamous carcinoma of the ampulla of Vater: a case report and literature review.

Drawing firm conclusions about the diagnosis of ampullary ASC is difficult because of the difficulty in acquiring both adenocarcinoma and SCC components by fine needle biopsy. The rarity of ASC of the AmV coexistent with gastric carcinoma makes it difficult to elucidate their clinicopathological characteristics, therapeutic strategies and overall prognosis. Surgical resection still remains the main treatment method.