A Gastric Composite Tumor with an Adenocarcinoma and a Neuroendocrine Carcinoma: A Case Report
A 70-year-old woman was admitted to our department with epigastric discomfort and nausea that have lasted for 1 month. Her past medical and family histories were unremarkable. At admission, the physical examination was also unremarkable.\nOn blood test, there was no leukocytosis or anemia, and liver function tests were normal. The levels of tumor markers were within the normal reference range, as follows: carcinoembryonic antigen (CEA), 2.39 ng/mL (normal, <5); CA 19-9, 17.59 U/mL (normal, <37). The esophagogastroduodenoscopy showed a 1.0×1.0 cm-sized ulcerative mucosal lesion at the greater curvature side of the antrum (). The patient underwent endoscopic ultrasound (EUS), which revealed a 1 cm-sized isoechoic mass in the mucosal layer of the greater curvature of the antrum ().\nThe abdominal computer tomography (CT) scan examination demonstrated no evidence of metastatic regional lymph nodes.\nThe pathologic examination of the endoscopic forceps biopsies showed a well differentiated, intestinal type adenocarcinoma. Endoscopic submucosal dissection (ESD) was performed. Microscopic sections of the resected specimen showed two components: the first component was a well-differentiated adenocarcinoma and the second was characterized as a neuroendocrine carcinoma. One area of transition between the two histological types was observed ().\nOn immunohistochemistry, the exocrine part was positive for cytokeratin p53. Neuroendocrine markers (chromogranin A, synaptophysin, and CD56) were positive in the neuroendocrine components.\nThe post-ESD course was uneventful and the patient was discharged on the 7th ESD day. For 12 months after the ESD, the patient has been under endoscopic, serological (CA 19-9, CEA, chromogranin A) and CT surveillance. The patient is doing well without evidence of disease recurrence.