Primary duodenal carcinoma suspected to arise from ectopic gastric mucosa: a case report.

BACKGROUND: Ectopic gastric mucosa mainly occurs in the duodenal bulb, and its etiology is thought to be congenital straying of gastric tissues. Primary duodenal carcinoma is a rare disease; however, reports of carcinoma arising from ectopic gastric mucosa are extremely rare. We report a case of primary duodenal carcinoma suspected to arise from ectopic gastric mucosa, which discovered as a result of duodenal stenosis. CASE PRESENTATION: The patient was a 71-year-old man with persistent weight loss and white stools. Enhanced computed tomography showed stenosis of the third portion of the duodenum and main pancreatic duct dilatation. Upper gastrointestinal endoscopy revealed irregularity of the duodenal mucosa from the anorectal side of the papilla of Vater to the stenosis of the third portion. No malignant cells were found by biopsies from the duodenal mucosa. Endoscopic ultrasonography did not detect the tumor in the pancreatic head. The possibility of a pancreatic tumor could not be ruled out based on findings of main pancreatic duct dilatation in the pancreatic head, and the patient had long-term poor oral intake because of duodenal stenosis; thus, surgical treatment was planned. Intraoperative findings showed palpable induration of the third portion of the duodenum and white nodules on the serosal surface. This was diagnosed as primary duodenal carcinoma, and pylorus-preserving pancreatoduodenectomy was performed. Histopathological diagnosis revealed ectopic gastric mucosa in the papilla of Vater and well-differentiated tubular adenocarcinoma invaded the normal duodenal submucosa and extended to the duodenal serosa. No mass lesion was detected in the pancreas, and an intraductal papillary mucinous neoplasm was observed in the branch pancreatic duct. The main pancreatic duct stricture was caused by the duodenal carcinoma invasion. CONCLUSIONS: This case of primary duodenal carcinoma was suspected to arise from ectopic gastric mucosa and review the relevant literature.

Component with abundant immune-related cells in combined hepatocellular cholangiocarcinoma identified by cluster analysis.

Combined hepatocellular cholangiocarcinoma (cHCC-CCA) is a heterogeneous tumor sharing histological features with hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). The tumor immune microenvironment (TIME) of cHCC-CCA is unclear. We compared the TIME of cHCC-CCA with that of HCC and iCCA. Twenty-three patients with cHCC-CCA after hepatectomy were evaluated in this study. Twenty-three patients with iCCA and HCC were also included. iCCA was matched for size, and HCC was matched for size and hepatitis virus infection with cHCC-CCA. Immune-related cells among the iCCA-component of cHCC-CCA (C-com), HCC-component of cHCC-CCA (H-com), iCCA, and HCC were assessed using multiplex fluorescence immunohistochemistry. Among C-com, H-com, iCCA, and HCC, multiple comparisons and cluster analysis with k-nearest neighbor algorithms were performed using immunological variables. Although HCC had more T lymphocytes and lower PD-L1 expression than iCCA (P < 0.05), there were no significant differences in immunological variables between C-com and H-com. C-com tended to have more T lymphocytes than iCCA (P = 0.09), and C-com and H-com had fewer macrophages than HCC (P < 0.05). In cluster analysis, all samples were classified into two clusters: one cluster had more immune-related cells than the other, and 12 of 23 H-com and eight of 23 C-com were identified in this cluster. The TIME of C-com and H-com may be similar, and some immunological features in these components were different from those in HCC and some iCCA. Cluster analysis identified components with abundant immune-related cells in cHCC-iCCA.

Coexistence of Magnetoelectric and Antiferroelectric-like Orders in Mn3Ta2O8.

In materials showing a linear magnetoelectric (ME) effect, unconventional functionalities can be anticipated such as electric control of magnetism and nonreciprocal optical responses. Thus, the search for new linear ME materials is of interest in materials science. Here, using a recently proposed design principle of linear ME materials, which is based on the combination of local structural asymmetry and collinear antiferromagnetism, we demonstrate that an anion-deficient fluorite derivative, Mn3Ta2O8, is a new linear ME material. This is evidenced by the onset of magnetic-field-induced electric polarization in its collinear antiferromagnetic phase below TN = 24 K. Furthermore, we also find an antiferroelectric-like phase transition at TS = 55 K, which is attributable to an off-center displacement of magnetic Mn2+ ions. The present study shows that Mn3Ta2O8 is a rare material that exhibits both ME and antiferroelectric-like transitions. Thus, Mn3Ta2O8 may provide an opportunity to investigate the physics associated with complicated interactions between magnetic (spin) and electric dipole degrees of freedom.