The phenomenon of neutrophil-tumor cell emperipolesis or phagocytosis has been documented by light microscopy in various human carcinomas, but little is known about the cellular pathological processes and the morphological changes involved. In an attempt to clarify the nature of this phenomenon, the authors' ultrastructural studies on the relationships among neutrophils and tumor cells in human gastric carcinomas are reviewed and analyzed. At the electron microscopy level, apoptotic neutrophils were found within vacuoles of adenocarcinoma cells in 2 cases. They showed either early apoptotic morphology with perinuclear chromatin aggregation but cytoplasm integrity or late apoptotic morphology with uniform, collapsed nucleus and tightly packed cytoplasmic granules. A light microscopy review of 200 cases of resected gastric carcinomas identified 22 cases (11%) that were characterized by neutrophil-tumor cell phagocytosis (cannibalism). TUNEL staining confirmed the presence of apoptotic neutrophils within the cytoplasm of the tumor cells. This study provides light and electron microscopic evidence of apoptotic neutrophils phagocytosed by gastric adenocarcinoma cells. The morphological features of neutrophil-tumor cell phagocytosis (cannibalism) would suggest a particular mechanism of tumor-immune escape in human gastric carcinoma.

Adenocarcinoma↗

PubMedDate not supplied

Mast cell interaction with tumor cells in small early gastric cancer: ultrastructural observations.

The authors studied the mast cells by light and electron microscopy in four small intramucosal early gastric cancers (EGC). Mast cells were found in the tumor stroma and among neoplastic cells of adenocarcinoma glands. Stromal and adenocarcinoma-infiltrating mast cells were ultrastructurally identified as T mast cells, and exhibited anaphylactic or piecemeal degranulation. Tumor cells in intimate contact with mast cells showed no cytopathic changes. These data do not support a mast cell-mediated cancer lysis, such as that reported in some systems in vitro. The interepithelial localization of T mast cell in adenocarcinoma glands is similar to that observed in some disease states, including interstitial cystitis, fibrotic lung disorders, and mucosal allergic reaction. The findings suggest that T mast cells may be involved in the pathophysiology of the host reaction to small intramucosal EGC.

Adenocarcinoma↗

PubMedDate not supplied

Eosinophil-tumor cell interaction in advanced gastric carcinoma: an electron microscopic approach.

BACKGROUND: Tumor-associated tissue eosinophils have been observed in human tumors and experimental tumor models, but their function is poorly understood. MATERIALS AND METHODS: One case of intestinal-type adenocarcinoma of the stomach, mainly infiltrated by eosinophils, is studied by light and electron microscopy, focusing on the relationships between eosinophils and tumor cells and on the nature of tumor cell death. RESULTS: Using light microscopy, eosinophils, single or in clusters, were present both in the stroma and within neoplastic glands. With electron microscopy, tumor cells in intimate contact with eosinophils revealed changes consistent with autophagic cell death such as chromatin condensation in small masses into the nucleus, dilation of the nuclear envelope, and numerous cytoplasmic vacuoles. The adenocarcinoma cells, not contacted by neutrophils, remained morphologically well preserved. CONCLUSIONS: Our ultrastructural study suggests the hypothesis of a direct relationship between eosinophil infiltration and induction of autophagic cell death in gastric adenocarcinoma cells.

Adenocarcinoma↗

PubMedDate not supplied

Perivascular mast cells in advanced gastric adenocarcinomas: an electron microscopic study.

Mast cells are frequently found in close proximity to blood vessels and have been implicated in tumour angiogenesis. The aim of the present ultrastructural study was to characterize, in detail, the mutual association between mast cells and microvasculature in 9 cases of advanced gastric carcinoma. Perivascular mast cells were ultrastructurally identified as T mast cells and exhibited piecemeal degranulation, indicative of a slow release of granule-stored contents. In two cases they were adjacent to endothelial cells showing vesiculo-vacuolar organelles, a newly-defined endothelial cell permeability structure. Collagen fibres and dispersed fibrous long-spacing collagen were found near T mast cells in one case, suggesting their role in perivascular collagen degradation and/or turnover. Mast cells were associated with microvascular basal lamina changes including irregular thickness, multiple layers and loose association with endothelial cells and pericytes, reminiscent of degenerating or regenerating blood vessels. In conclusion, our ultrastructural study suggests that mast cells contribute to the remodelling of existing vessels by a slow release of granule-stored contents in advanced gastric adenocarcinomas.

Aged↗

PubMedDate not supplied

[Correlation of histopathology and application of CA 19/9 monoclonal antibodies in the diagnosis of Vater's ampulla epithelial neoplasms].

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Adult↗