Neutrophil-rich gastric carcinoma in the integrated cancer registry of eastern Sicily, Italy.

BACKGROUND/AIM: Neutrophil-rich carcinoma is a variant of gastric carcinoma that has not been well-studied or characterized. The purpose of the present study was to reveal the incidence and clinicopathological findings compared to ordinary gastric carcinoma. PATIENTS AND METHODS: A population-based series of 430 gastric cancers, identified between 2003 and 2006 from the province of Messina (insular Italy; population, 662,450), was used. The number of tumor-infiltrating neutrophils was assessed in a semi-quantitative manner using the mean value of 20 non-overlapping high-power fields (magnification, 400; 0.08 mm(2)). Tumors with >10 neutrophils per 20 high-power fields were arbitrarily considered as neutrophil-rich gastric carcinomas. Moreover, MUC1 immunohistochemical expression was investigated to show possible correlation with neutrophil infiltration in gastric carcinomas. RESULTS: Among 193 gastric cancers resected for curative purposes, 30 (15.54%) were represented by neutrophil-rich gastric carcinomas. These tumors occurred more frequently in patients aged more than 72 years (p<0.05), showing an inverse correlation with mucinous subtype according to the WHO classification (p<0.001) and expressed MUC1. However, intensity and distribution of MUC1 was heterogeneous, and independent of neutrophil infiltration within the tumor stroma. CONCLUSION: Neutrophil-rich carcinoma seems to represent a distinctive morphological variant of gastric carcinoma, although the true mechanism for the infiltration of neutrophils is still unclear.

Apoptotic-like tumor cells and apoptotic neutrophils in mitochondrion-rich gastric adenocarcinomas: a comparative study with light and electron microscopy between these two forms of cell death.

Mitochondrion-rich adenocarcinomas represent a rare variant of gastric adenocarcinomas composed predominantly of columnar adenocarcinoma cells with eosinophilic cytoplasm, a strong supranuclear immunoreactivity for antimitochondrial antibody, and a marked neutrophil infiltration associated to tumor cell death. The purpose of this work is to investigate, using correlated light and electron microscopy, mitochondrion-rich gastric adenocarcinomas focusing on the nature of the death in neoplastic cells and in infiltrating neutrophils. Adenocarcinoma cells, single or in small clusters, showed convoluted nuclei, irregularly condensed chromatin, loss of microvilli, and nuclear envelope dilatation. No nuclear fragmentation was observed in these dying cells and the plasma membrane did not show signs of disruption. These ultrastructural findings represent intermediate aspects between apoptosis and necrosis and are compatible with apoptosis-like programmed cell death. By contrast, some infiltrating neutrophils showed ultrastructural signs of classic apoptosis such as chromatin condensation into compact geometric (globular, crescentshaped) figures, tightly packed cytoplasmic granules and intact cell membrane. Our study provides ultrastructural evidence of apoptosislike tumour cell death in mitochondrion-rich gastric carcinomas and confirms that stereotyped outcome either as apoptosis or necrosis of tumor cells cannot always be expected in human neoplasms.

Abnormal nuclear structures (micronuclei, nucleoplasmic bridges, and nuclear buds) in a pleomorphic giant cell carcinoma of the stomach.

A rare case of pleomorphic giant cell carcinoma of the stomach in a 70-year-old man is reported. Characteristic microscopic findings included a general lack of architectural cohesiveness, aggregates of mononucleated or multinucleated giant cells, extensive areas of coagulative necrosis, and numerous mitoses. Immunohistochemically, tumor cells displayed cytoplasmic immunoreactivity for cytokeratin AE1/AE3 as well as overexpression of p53 and Ki-67. Electron microscopy revealed paranuclear tonofilaments bundles in giant cells confirming their epithelial nature. Furthermore, giant cells contained two or more nuclei with heterogeneous size, nucleoplasmic bridges, nuclear buds, and micronuclei. Similar abnormal nuclear structures have been closely related to breakage-fusion-bridge type of mitotic disturbances in tumor cell lines, and have not been previously reported in a human tumor.