Pleomorphic Adenoma With Disrupted Biphasic Ductal Structures Attributed to Lymphoid Infiltration: A Case Report.

Pleomorphic adenoma (PA) is a benign salivary gland tumor with diverse cytomorphological and architectural features, typically presenting biphasic ductal structures within a chondromyxoid matrix. We report a unique case of PA where dense lymphoid infiltration disrupted these structures, resulting in duct-like slit structures lined with a single layer of spindle cells, lacking the biphasic pattern. These spindle cells demonstrated myoepithelial nature, confirmed by positive immunostaining for pan-cytokeratin, S100 protein, and calponin.

Ovarian mucinous cystic tumor with an overwhelming fundic gland differentiation.

An ovarian mucinous cystic tumor where fundic glands were broadly and evenly distributed. All components were FOXA2-positive. The diagnosis is difficult between "mucinous cystadenoma with fundic gland differentiation" and "monodermal cystic teratoma composed of gastric tissue derived from endoderm".

Discovery of YS-1 as a cell line of gastric inflammatory cancer-associated fibroblasts.

Background: Inflammatory cancer-associated fibroblasts (iCAFs) was first identified by co-culture of pancreatic stellate cells and tumor organoids. The key feature of iCAFs is IL-6/αSMA. We examine this phenomenon in gastric cancer using two cell lines of gastric fibroblasts (HGF and YS-1).

Gastric Cancer With the Increased Nicotinamide N-methyltransferase-positive Stromal Cells Includes Unfavorable Prognosis-related Cancer-associated Fibroblasts.

Background/aim: "Stromal high expression" of Nicotinamide N-methyltransferase (NNMT), previously reported as a poor prognostic factor of gastric cancer, was based on immunohistochemical H-score. However, this could simply indicate an increase in cancer-associated fibroblasts (CAFs) because NNMT is positive for fibroblasts. To verify this, the proportion and staining intensity of stromal NNMT-positive stellate/spindle cells were evaluated separately and examined for its association with related proteins (H3K4me3, H3K27me3, and LOXL2).