Gastric adenosquamous carcinoma with an elevated serum level of alpha-fetoprotein: A case report

BACKGROUND: Gastric adenosquamous carcinoma (ASC) is rare and characterized by coexisting of adenocarcinoma andsquamous carcinoma within the same tumor. We present a female patient with gastric ASC who had an elevated serum level of alpha-fetoprotein (AFP), which decreased to normal levels after a laparoscopic distant radical gastrectomy in a short period. The clinicopathological features in AFP-producing gastric cancer (GC) are discussed, as well as potentially available prognostic predictors. CASE SUMMARY: A 50-year-old woman presented to our department with a chief complain of a 6-mo history of bloating. She had no basic diseases including heart diseases and respiratory diseases, and she also denied any prior history of dysphagia, hematemesis, melena, rectal bleeding, hematochezia, or unintentional weight loss. Based on her symptoms, an esophagogastroduodenoscopy was performed, showing an annular cavity lesion 3 cm from the pylorus with a diameter of 6 cm. A biopsy of the lesion showed gastric ASC, whereas the pylorus biopsy showed normal mucosa. The patient further received an enhanced computed tomography scan which demonstrated an invasive lesion close to the pylorus with a still clear margin of the tumor to peripheral organs such as the pancreas and liver. Scattered lymph nodes were visible around, whereas no sign of liver metastasis was discovered. Serum tumor markers including carcinoembryonic antigen (CEA), cancer antigen 199 (CA199), CA724, CA125, and CA242 were all normal, while the level of serum AFP increased to 172 ng/mL. A laparoscopic distant radical gastrectomy was performed after exclusion of surgical contraindications. Postoperative pathology results showed that the tumor displayed an ulcerated ASC phenotype (90% of medium to highly-differentiated squamous cell carcinoma, 10% of poorly differentiated adenocarcinoma. Surprisingly, the serum level of AFP decreased to normal level on post operation day 5. The tumor cells were positive for CK5/6, p63, and CEA, and negative for AFP and Epstein-Barr encoding region. CONCLUSION: We presented a rare case of gastric ASC with elevated serum AFP level, which may be new subtype of AFP-producing GC. Follow-up detection of serum AFP might be a useful tool to predict patient prognosis.