Endoscopic diagnosis of a gastric small cell carcinoma with liver metastasis

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]).

Fig. 1 Contrast-enhanced computed tomography, showing multiple hepatic tumors over both lobes and an enhancing mass at the mid gastric body (arrow).

Upper endoscopy revealed a mucosal bulge with central ulceration at the mid gastric body ([Fig. 2]).

Fig. 2 Endoscopic view showing a mucosal bulge with central ulceration at the mid gastric body.

The histopathological assessment of the biopsy specimens demonstrated nests of small cells with hyperchromatism and scanty cytoplasm ([Fig. 3 a]).

Fig. 3 a Photomicrograph showing nests of small cells in the gastric mucosa with hyperchromatism and scanty cytoplasm (hematoxylin and eosin, magnification × 40). b Immunohistochemical staining positive for chromogranin. c Immunohistochemical staining positive for CK7.

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.

Competing interests: None

Endoscopy_UCTN_Code_CCL_1AB_2AD_3AB

The page number has been corrected to E283 – E284.

References

• 1 Kusayanagi S, Konishi K, Miyasaka N. et al . Primary small cell carcinoma of the stomach.  J Gastroenterol Hepatol. 2003;  18 743-747
• 2 Namikawa T, Kobayashi M, Okabayashi T. et al . Primary gastric small cell carcinoma: report of a case and review of the literature.  Med Mol Morphol. 2005;  38 256-261
• 3 Vrouvas J, Ash D V. Extrapulmonary small cell cancer.  Clin Oncol (R Coll Radiol). 1995;  7 377-381
• 4 Tanemura H, Ohshita H, Kanno A. et al . A patient with small-cell carcinoma of the stomach with long survival after percutaneous microwave coagulating therapy (PMCT) for liver metastasis.  Int J Clin Oncol. 2002;  7 128-132