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.

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.

Morphological evidence of neutrophil-tumor cell phagocytosis (cannibalism) in human gastric adenocarcinomas.

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.

Prognostic value of intratumoral neutrophils in advanced gastric carcinoma in a high-risk area in northern Italy.

Several lines of evidence indicate that neutrophils act nonspecifically against tumor cells. The correlation between tumor-infiltrating neutrophils (TINs) and clinicopathological features remains unclear and deserves to be investigated. To analyze the prognostic influence of TINs in gastric carcinoma, the authors selected 273 patients with advanced gastric carcinoma who underwent gastrectomy at Cremona Hospital (Lombardia, Italy) between 1990 and 1995 and followed them for a period of 5 years.

Ultrastructural observations on the microvasculature in advanced gastric carcinomas.

The ultrastructural features associated with vascular permeability in 9 cases of advanced gastric carcinomas were studied, and compared with that of control non-neoplastic mucosa. Tumour microvasculature showed features in common with those of control mucosa, including complete basal lamina, well-developed interendothelial junctions, fenestrations and caveolae. Some tumour blood vessels showed endothelial cell swelling accompained by luminal narrowing and perivascular fibrosis.

Small early gastric cancer with special reference to macrophage infiltration.

The authors investigate the tumor-infiltrating cells in small early gastric cancer (EGC) (<10 mm) and describe the ultrastructural features and interactions of macrophages with tumor cells and other inflammatory cells. Sections from 20 small EGCs were stained by immunohistochemical methods for CD20, UCHL1, CD4, CD8, and CD68 (electron microscopic examination was used in 6 of the 20). In all of the tumors, CD68-positive macrophages accounted for most tumor-infiltrating cells, with UCHL1-positive T lymphocytes, eosinophils, and neutrophils being the next most frequent.

Clinicopathological features of early gastric cancer in younger versus older patients in a high incidence area of northern Italy.

Aims: The relationship between the clinicopathological features of early gastric cancer and age were analysed in a retrospective study of 168 patients.

Methods: 168 patients, residents of the Region of Cremona, who had undergone surgery in the period 1978 to 1990 for early gastric cancer, were divided into two groups by age and compared. Group I (n = 89) consisted of patients less than 65 years of age and Group II (n = 79) of patients between 66 and 85 years of age.

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.

Microsatellite instability in early gastric cancer.

Microsatellite replication errors (RERs), consisting in random tumour-associated allele contractions or expansions, represent a frequent genetic alteration in gastric cancer and appear to be associated with important clinicopathologic parameters. To verify the role of microsatellite instability in the initial phases of gastric carcinogenesis, we analysed the status of II microsatellites in paired microdissected samples of tumour and unaffected mucosa from 30 cases of early gastric carcinoma. Fifteen tumours (50%) demonstrated RERs: these included 7 cases with RERs at one locus and 8 cases with RERs at 2 or more loci.

Report of an intrapulmonary solitary fibrous tumor: fine-needle aspiration cytologic findings, clinicopathological, and immunohistochemical features.

The authors describe a rare case of intrapulmonary solitary fibrous tumor (SFT). Morphologically, the tumor showed a disorganized or "patternless" arrangement of plump to spindle cells in a collagenous stroma. Tumor cells were immunoreactive for vimentin, but not for keratin, carcinoembryonic antigen, epithelial membrane antigen, factor-VIII related antigen, S-100 protein, desmin, and actin.

Ultrastructural study of the vascular response in small early gastric cancer.

The microvasculature of the stroma of four cases of small early gastric cancer (EGC) was investigated by conventional electron microscopy. Severe damage to small and large fenestrated capillaries was observed around endothelium-adherent, partially degranulated neutrophils. The findings suggest the existence of neutrophil-mediated injury of endothelial cells during the development of inflammatory responses in small EGC.

Neutrophil interaction with tumour cells in small early gastric cancer: ultrastructural observations.

The authors studied the neutrophil inflammatory reaction by light and electron microscopy in 4 small early gastric cancers (three tubular adenocarcinomas and one adenocarcinoma with signet-ring cell component), selected for the absence of coagulative necrosis and ulceration. Neutrophils showed ultrastructural signs of activation such as aggregation, adhesion and lipid bodies. Some neutrophils were found to be in intimate contact with the intact tumour cells and with those that displayed a varying degree of damage.

Minute and small early gastric carcinoma with special reference to eosinophil infiltration.

The authors examined 25 minute early gastric cancers (EGC) and 13 small EGC in order to investigate the incidence and possible causes for the infiltration of eosinophils. The degree of eosinophil infiltration was higher in tumour stroma than in adjacent normal-appearing mucosa; this correlation was statistically significant (P < 0.001).

Immunocytochemical detection of lactoferrin in human gastric carcinomas and adenomas.

In gastric carcinomas, including 20 cases of intestinal type and 10 cases of diffuse type, in adenomas with mild to severe dysplasia (20 cases), and in hyperplastic polyps (10 cases), the presence of lactoferrin was investigated by immunohistochemistry. Incomplete or complete intestinal metaplasia or both and normal gastric mucosa were also tested. Preoperative hematocrit and serum iron levels (18 patients) were recorded.

Morphological demonstration of non-heme iron and iron-binding proteins in placentas from cases of congenital nephrotic syndrome of Finnish type.

Two placentas (gestational age 36 and 39 weeks respectively), obtained from Congenital Nephrotic Syndrome of Finnish type (CNF) cases, have been studied by histochemistry in relation to the presence of non-heme iron and iron-binding proteins (ferritin, transferrin and lactoferrin). Ten control placentas of gestational age ranging from 35 to 40 weeks have been also examined. Employing the Prussian Blue ferrocyanide method, an intense positive reaction of the trophoblastic basament membrane (TBM) was observed only in cases of CNF.

Vascular changes in placentae from cases of materno-fetal rhesus incompatibility.

Three placentae from cases of materno-fetal Rhesus incompatibility have been studied electron microscopically. An abnormal villous vascular arrangement with dilated capillaries and newly formed vessels and stromal edema were the most characteristic findings. Syncytiotrophoblastic trophic changes and focal thickening of the trophoblast basement membrane were also found.

Persistent neonatal normoinsulinaemic hypoglycaemia.

A case is recorded of persistent neonatal hypoglycaemia characterized by early onset, normoinsulinaemia and improvement following glucagon therapy. The pancreatic A cell were very few in number and were mainly degranulated. There was a slight increase of B cells, but changes in cells producing somatostatin and human pancreatic polypeptide were not encountered.

Eosinophilic pancreatitis in the newborn infant of a diabetic mother.

The authors have studied the pancreas of a premature female infant born to a diabetic mother. The findings included a peri-insular eosinophilic leucocyte infiltration, macropolinesia and a marked increase in B cells. In the exocrime parenchyma small B cells aggregates were also observed.