Clinicopathological analysis of 10 cases of gastric small cell neuroendocrine carcinoma

YAO Juan; YUAN Hongmei; ZHAO Hongmei; LI Ping; JIA Sujian; YANG Guizhen

Abstract：Objective To analyze clinical and pathological characteristics of 10 cases of gastric small cell neuroendocrine carcinoma ( SCNEC-G) and to explore the main points of diagnsis and differentiate diagnosis, hoping to improve the accuracy of patho-logical diagnosis and provide the basis for the comprehensive treatment. Methods From 2010 to 2015, the tissue sections from SC-NEC-G specimens of 10 cases underwent radical operation were observed by light microscopy. The tissue sections were labeled by im-munohistochemistry and the expression of synaptophysin( Syn) , chromogranin ( CgA) , neural cell adhesion molecule ( CD56) , thyroid transcription factor-1 ( TTF-1) and Ki-67 were analyzed. Results Under light microscope, the tumor cells were arranged irregularly with invasive growth potential. The arrangement of cancer cells was diffuse and different sized nest or spindle-shaped structures. Some of the cases showed focal pseudoglandular pattern. The internal surface of the tumors showed nuclear debris and coagulative necrosis. Cancer cells were small, round, oval, spindle-shaped with hyperchromatic nuclei, nucleoli and morenuclear fission. The invasion of 10 cases of gastric cancer was from deep muscle layer to whole layer. There were infiltrations in peripheral adiposetissue in some cases. All samples had nerve invasion and intravascular cancer embolus. The percentages of 10 SCNEC-G samples with positive to strong positive immunoreactivity were 80. 0%, 70. 0%, 80. 0%, 40. 0% and 100. 0% for Syn, CgA, CD56, TTF-1 and Ki-67, respectively. Conclu-sion SCNEC-G has a higher sensitivity to neural markers, while part of some cases also express TTF-1. In some metastatic TTF-1 pos-itive small cell carcinoma of unknown primary lesion, we should consider the possibility of SCNEC-G.