Endoscopic diagnosis of a gastric small cell carcinoma with liver metastasis

Abstract

Primary small cell carcinomas of the stomach are extremely rare, accounting for less than 0.1 % of primary gastric cancers [1]. The clinical behavior of primary gastric small cell carcinoma is as aggressive as that of small lung cancer [2]. Distal metastases are frequently observed at initial presentation [3]. Small cell carcinomas proliferates mainly in the submucosal layer like a carcinoid tumor [1, 4]; however, the tumor may have endoscopic features identical to those of gastric adenocarcinoma [1]. Preoperative diagnosis of gastric small cell carcinoma is difficult because of its histological heterogeneity and microscopic resemblance to malignant lymphoma or undifferentiated adenocarcinoma [1, 4]. We report here a case of primary small cell carcinoma of stomach with liver metastasis, which was correctly diagnosed with endoscopic and liver biopsy. A 71-year-old man was referred to our institution for evaluation of multiple hepatic tumors. His past medical history was unremarkable. Physical examination revealed jaundice and a slightly distended abdomen. Laboratory data included a hematocrit of 40.9 % (normal 42 % -52 %) and a total bilirubin level of 3.2 mg/dl (normal 0.2 -1.2 mg/dl); the alpha-fetoprotein level was within normal limits. Chest radiography was unremarkable. Contrast-enhanced computed tomography showed multiple hepatic tumors over both lobes and an enhancing mass at the mid gastric body (• " Fig. 1).Upper endoscopy revealed a mucosal bulge with central ulceration at the mid gastric body (• " Fig. 2). The histopathological assessment of the biopsy specimens demonstrated nests of small cells with hyperchromatism and scanty cytoplasm (• " Fig. 3 a). Immunohistochemical staining revealed positivity for chromogranin (• " Fig. 3 b) and CK7 (• " Fig. 3 c). Immunostains for CEA, CK20, S100, TTF-1, and P53 were negative. Similar histopathological findings were obtained from the biopsy specimens taken from the liver tumors. A diagnosis of gastric small cell carcinoma with liver metastasis was made. The patient refused chemotherapy and died of hepatic failure 3 months later.