Composite Glandular and Endocrine Tumors of the Stomach With Pancreatic Acinar Differentiation

Abstract

Composite tumors of the stomach consisting of mixed glandular and endocrine components are rare. We report 3 cases of composite glandular and endocrine tumors with pancreatic acinar differentiation in the stomach with their clinicopathologic findings. The patients' presenting symptoms were variable and included abdominal pain, gastrointestinal hemorrhage, and weight loss. One patient with abdominal pain also had an elevated serum lipase level, clinically mimicking acute pancreatitis. The histology of these tumors was similar. They showed admixture of well-differentiated endocrine components with acinar and glandular components. The glandular component consisted of columnar epithelial cells resembling gastric foveolar or intestinal goblet cells, consistent with a well-differentiated adenocarcinoma. A panel of histochemical and immunohistochemical stains was performed, which included PAS, Alcian blue, Mib1, CEA, cytokeratin 7, cytokeratin 20, Muc2, Muc5AC, chromogranin, synaptophysin, trypsin, chymotrypsin, lipase, insulin, gastrin, serotonin, and pancreatic polypeptide. While the immunoreactivity for cytokeratin 7, cytokeratin 20, Muc2, Muc5AC, and CEA was largely restricted to the glandular component, the endocrine and pancreatic acinar markers showed marked variability and overlap. All cases showed immunoreactivity for at least one of the exocrine pancreatic enzymes, and all expressed endocrine differentiation. Some degree of amphicrine differentiation was suggested in all cases. Two cases showed metastases in perigastric lymph nodes, which histologically resembled the primary tumor. In summary, these tumors represent another distinct type of composite glandular and endocrine gastric neoplasm with pancreatic acinar differentiation.

Acinar Cell Carcinoma of the Pancreas: New Genetic and Treatment Insights into a Rare Malignancy

“…Tumors with acinar cell differentiation arising from the stomach and the colon have been reported previously [11][12][13]; however, endoscopic evaluation did not demonstrate tumor elsewhere in the gastrointestinal tract in either of our patients. Because neither patient underwent surgical exploration, one potential explanation for this may be the presence of a small, radiographically occult primary pancreatic lesion.…”

Goblet cell carcinoids and other mixed neuroendocrine/nonneuroendocrine neoplasms

“…3), variable combination of morphological aspects have been reported, and an attempt to list all reported cases would fail to be comprehensive. In the stomach peculiar aspects include cases showing at immunohistochemical and ultrasctructural levels the presence of amphicrine features [77], also in liver metastases [57], and pancreatic-like acinar differentiation in the exocrine component [16,31]. As well, in the small and large intestine MEEC cases have been documented, showing both well-differentiated [32] and poorly differentiated features [61,71] of the neuroendocrine component.…”

“…This lack of standardization created several controversies in both fields of tumor recognition and treatment of these lesions. In addition, especially in pulmonary and gastroenteropancreatic locations, a relatively wide spectrum (and possibly a continuum) of neuroendocrine differentiated tumors exist including tumors with wellrepresented (>30% of tumor area) neuroendocrine cell component and tumors with scattered neuroendocrine cells only [1,31,49,51,53,62].…”

The grey zone between pure (neuro)endocrine and non-(neuro)endocrine tumours: a comment on concepts and classification of mixed exocrine–endocrine neoplasms

“…This lack of standardization created several controversies in both fields of tumour recognition and treatment of these lesions. In addition, especially in pulmonary and gastroenteropancreatic sites, a relatively wide spectrum (and possibly a continuum) of NE-differentiated tumours does exist including tumours with wellrepresented (>30% of tumour area) NE cell component and tumours with scattered NE cells only [1,32,40,42,43,49].…”