α-fetoprotein-producing gastric carcinoma: A case report of a rare subtype and literature review.

α-fetoprotein (AFP)-producing gastric carcinoma is a rare type of gastric cancer, and the characteristics have not yet been fully elucidated. The present study reports the case of a patient with this type of gastric cancer. A 66-year-old male was referred to the Department of Gastrointestinal Surgery, Qianfoshan Hospital, Shandong University (Jinan, China) with a 20-day history of retrosternal pain. A computed tomography (CT) scan revealed a thickening of the wall of the cardia and massive lymph node swelling in the region of the lesser curvature of the stomach. A laboratory investigation revealed that the serum AFP levels of the patient were elevated to 46.49 ng/ml (normal level, <12.00 ng/ml), and the serum carcinoembryonic antigen (CEA) levels were 382.22 ng/ml (normal range, <5.00 ng/ml). An endoscopy revealed an elevated tumor and AFP-producing gastric cancer was diagnosed. As the tumor was surgically unresectable, the patient received systemic adjuvant chemotherapy [consisting of 1 cycle of oxaliplatin (150 mg; day 1)-fluorouracil(1.0 g; days 2-6)-calcium folinate (0.3 g; days 2-6), 4 cycles of paclitaxel (80 mg; day 1 and 8, repeated day 21) and capecitabine (1,000 g/m2, twice daily; days 1-14, repeated day 21), and 2 cycles of oxaliplatin (130 mg/m2; day 1, repeated day 21) and S-1 (100 mg/d; day 1- day 14; repeated day 21)]. During the chemotherapy intermission, the patient experienced partial remission; the serum AFP levels remained between 44.5 and 32.7 ng/ml, and serum CEA levels decreased to a normal level. The CT scan revealed that the enlarged lymph nodes of the patient had decreased in size. During the preoperative examinations, an abdominal CT scan revealed no metastasis to the liver. A radical gastrectomy was performed on October 20, 2014. Additionally, the tumor did not demonstrate the diffusion of AFP. The histopathological examination revealed a poorly differentiated adenocarcinoma, with local and neuroendocrine differentiation and no hepatoid features. According to these histopathological findings, the tumor was diagnosed as AFP-producing non-hepatoid adenocarcinoma of the stomach. The patient was treated with systemic immunity-enhancing therapy and has been free of recurrence for 2 months. The present study describes a rare case of AFP-producing non-hepatoid adenocarcinoma of the stomach, with a review of the literature and an investigation of the clinical features.