Composite glandular-endocrine cell carcinoma of the stomach. Report of two cases with goblet cell carcinoid component

Composite glandular-endocrine cell carcinoma (CGECC) is recognized as a special type of gastric tumor composed of ordinary adenocarcinoma and neuroendocrine tumors. Goblet cell carcinoid (GCC) is a well-established type of appendiceal carcinoid, but the GCC component has not been well delineated in CGECC of the stomach. We report on two gastric CGECCs with a GCC component, analyzing the histologic components by immunohistochemistry. On initial biopsy, both cases were diagnosed as signet-ring cell carcinoma. However, the resected tumors consisted of three components: signet-ring cell carcinoma, GCC, and glandular adenocarcinoma. Although some signet-ring carcinoma cells and goblet carcinoid cells were indistinguishable by hematoxylin and eosin staining, E-cadherin immunostaining disclosed a definitive difference regarding the staining pattern in these cells. Both patients are well, with no recurrent tumor for about 10 years of follow-up. CGECC with a GCC component may have been confused with conventional adenocarcinoma with signet-ring cells. In cases of advanced signet-ring cell carcinoma with good prognosis, the possibility of such CGECC has to be considered.