[Goblet cell adenocarcinoma in the digestive system: a clinicopathological analysis of 22 cases].

Objective: To investigate the clinical features, morphological characteristics, immunophenotype, and differential diagnosis of goblet cell adenocarcinoma (GCA) in the digestive system. Methods: The clinicopathological data, morphological characteristics, immunophenotypes of 22 cases of GCA in the digestive system diagnosed from January 2010 to January 2021 were collected. Meanwhile, 25 cases of neuroendocrine neoplasm (NEN) and 24 cases of adenocarcinoma were used as controls. Relevant literature was also reviewed. Results: There were 16 males and 6 females, aged from 36 to 79 years with an average of 56 years. The anatomical sites of the 22 GCA were mostly appendix (17 cases) and occasionally extra-appendix (5 cases), including 3 cases in stomach, 1 case in duodenum and 1 case in anal. All 17 cases of appendiceal GCA were pure GCA. Among the 5 cases of extra-appendiceal GCA, One case of gastric GCA was pure, two cases of gastric GCA with NEN or adenocarcinoma, duodenal GCA with NEN and adenocarcinoma, anal GCA with NEN.Low-grade GCAs were composed of goblet, Paneth and neuroendocrine cells, which were arranged in intestinal crypt tubular or cluster structures and distributed in the wall of digestive system. The tubular and cluster structures lacked adhesion. Goblet cells were columnar, located in the base, with clear cytoplasm, small nuclei, inconspicuous atypia, and uncommon mitoses. Extracellular mucus and signet-ring cells with nuclear variations could be seen in some cases. Nerve fiber bundle invasion and tumor thrombus in vessels were often present. High-grade GCAs lacked tubular and cluster structures, and their histological structures were more complex. Tumor cells expressed mixed neuroendocrine and glandular epithelial markers. Similar to the expression patterns of synaptophysin and chromogranin A, CD200 and INSM1 were also dot-like or patch-positive in GCA. Conclusions: GCA is an infrequent tumor of the digestive system and shows the bi-directional differentiation characteristics of neuroendocrine and glandular epithelium. Accurate diagnosis and staging are related to its prognosis.