Advanced gastric endocrine cell carcinoma with distant lymph node metastasis: a case report and clinicopathological characteristics of the disease.

Gastric pure endocrine cell carcinoma (ECC) is extremely rare. ECC occasionally shows multidirectional differentiation; that is, adenocarcinomatous and/or squamous proliferation. Because gastric ECC has aggressive biological behavior and shows frequent metastasis to liver and lymph nodes even in the early stage, the prognosis of patients having this disease is extremely poor. We treated a 75-year-old woman with advanced gastric pure ECC with total gastrectomy and lymph node dissection, and reviewed all the previously reported cases of this disease. We compared the clinicopathological findings of ECC with those of gastric carcinoma (GC) and found that ECC had significantly more frequent invasion to lymphatic and vascular lumens ( P < 0.01) and more frequent metastasis to lymph nodes ( P < 0.01) and liver ( P < 0.05) compared to GC. Gastric ECC smaller than 5 cm in the greatest dimension showed a higher percentage of advanced lesions (>T2) than GC ( P < 0.05), which could result in the difficulty of finding early ECC. The findings of the analyses we made in this report may account for the poor prognosis of this disease.