Gastrointestinal Obstruction due to Solitary Lymph Node Recurrence of Alpha-Fetoprotein-Producing Gastric Carcinoma with Enteroblastic Differentiation
A 75-year-old woman with a history of diabetes mellitus, hyperlipidemia and osteoporosis consulted her local physician for occasional upper abdominal discomfort. She was referred and admitted to our hospital for evaluation and treatment. No abdominal tumor mass or superficial lymph nodes were palpable. Routine laboratory findings were unremarkable, with the exception of slightly elevated serum AFP (10.5 ng/ml). Gastroscopy revealed a 20-mm type 2 tumor, primarily in the pyloric region. Histological examination of gastroscopic biopsies confirmed gastric adenocarcinoma (moderately differentiated tubular adenocarcinoma), but no detailed information was obtained. Barium enema confirmed a type 2 tumor in the pyloric region. No obvious lymph node metastasis or remote metastasis was observed on contrast-enhanced computed tomography (CT).\nThus, with a provisional diagnosis of gastric adenocarcinoma, we performed laparoscopic distal gastrectomy with lymph node dissection. Macroscopically, the type 2 tumor was located near the pylorus and measured 20 × 15 mm (fig. ). It invaded vertically into the muscularis propria, and two regional lymph node metastases were observed microscopically. Histological examination demonstrated the presence of adenocarcinoma with a tubulopapillary growth pattern (fig. ). Tumor cells were cuboidal in shape with characteristically clear cytoplasm. Periodic acid-Schiff (PAS) stain showed that the clear cytoplasm was almost filled with fine granular glycogen (fig. ). The tumor cells were negative in mucin in either alcian blue-PAS stain, but also in the immunohistochemistry for MUC2 (goblet cell mucin) or MUC5AC (foveolar mucin).\nImmunohistochemically, tumor cells were positive for AFP (fig. ), carcinoembryonic antigen (CEA) (fig. ), caudal-type homeobox transcription factor 2 (CDX2) (fig. ) and common acute lymphoblastic leukemia antigen (CD10) (fig. ). AFP was mainly expressed in the cytoplasm whereas CEA was positive in the apical surfaces of tumor cells. CDX2 was expressed strongly in the tumor cell nuclei. CD10 was positive in the luminal surfaces in some tumor cells. The tumor was immunohistochemically negative in synaptophysin, chromogranin A and CD56 (NCAM), though a few chromogranin A and few synaptophysin-positive neuroendocrine cells were found scattering among clear carcinoma cells. Human chorionic gonadotropin was not found in tumor cells. The final diagnosis was AFP-producing gastric carcinoma with enteroblastic differentiation. Lymph node metastases showed similar histological and immunohistochemical results as the primary site.\nThe patient had an uneventful postoperative course, and AFP levels normalized to 3.7 ng/ml. She was followed without adjuvant chemotherapy because of her advanced age. However, 15 months after the initial surgery, serum levels of AFP increased to 279.4 ng/ml, and fluorodeoxyglucose positron emission tomography (FDG-PET) revealed No. 8p lymph node recurrence (fig. ). Therefore, chemotherapy combining cisplatin (CDDP) and etoposide (VP-16) was conducted for six courses. The size of lymph node recurrence initially decreased, but she consulted our hospital for upper abdominal pain and vomiting 26 months after the initial surgery. A CT scan revealed gastrointestinal obstruction near the anastomotic site of gastroduodenostomy due to No. 8p lymph node recurrence (fig. ). As it was difficult to continue chemotherapy, she underwent palliative gastrojejunostomy. The surgery temporarily restored adequate oral intake, but she received repeated blood transfusions for uncontrollable gastrointestinal bleeding, and serum levels of AFP increased to 8,634 ng/ml. 29 months after initial surgery, the patient died.