Prognostic value of histopathological grading in canine extramedullary plasmacytomas.

The canine extramedullary plasmacytoma (cEMP) has recently been the subject of numerous investigations, indicating that the histomorphologic diagnosis is often difficult because of the variety of morphologic features. Therefore, the objective of this study was to establish a subclassification scheme for cEMPs and to evaluate correlations between the types and malignancy. Retrospectively, 117 cEMPs, all immunohistochemically characterized by a monoclonal immunoglobulin light-chain expression, were collected and assigned to morphologic types.

[Diabetes mellitus in young dogs and cats. Case reports and a comparison with relevant literature].

Cases of diabetes mellitus in young cats and dogs (younger than five years) are described rarely in contrary to reports in older patients (older than eight years). Histological alterations of pancreatic islets in young canine and feline diabetic patients represent the main issue of this publication together with the regenerative capacity of insulin-producing cells in these patients. These regenerative phenomenons of differentiated islet cells (replication) or their progenitors (neogenesis deriving from stem cells) are detected in young cats and dogs in isolated cases whereas they are in general missing in older patients.

p53 mutations in childhood thyroid tumours from Belarus and in thyroid tumours without radiation history.

Mutations in the p53 tumour-suppressor gene (exons 5-8) were investigated in 31 Belarussian childhood thyroid tumours (24 cases of papillary thyroid carcinoma, 3 benign tumours and 2 cases each of thyroiditis and goiter); 33 thyroid tumours from juveniles and adults without radiation exposures (25 carcinomas of various histological types, including 11 papillary carcinomas and 8 adenomas) and 6 tumours from adults (4 papillary carcinomas, 1 adenoma, 1 goiter) served as controls. The mutational spectrum of p53 differed greatly between the childhood thyroid carcinomas from Belarus and the control groups. In the control groups of 29 malignant thyroid tumours, 7 different mutations were detected on exons 5-8, none of which occurred among the 15 papillary carcinomas in this group.

Botryoid-type embryonal rhabdomyosarcoma of liver in a young cat.

An unusual malignant mesenchymal tumor arising in the liver of a 2-year-old cat is described. Histologically, the tumor showed considerable variation in growth pattern, cellularity, and cell types. Phenotypical diversity was confirmed by immunohistochemistry, showing expression of desmin, vimentin, S-100, and neuron-specific enolase in various areas of the tumor.

Laser beam microdissection in the diagnosis of cutaneous B-cell lymphoma.

Interpretation of molecular analyses of cutaneous lymphoid infiltrates may be difficult because a heterogeneous group of cells in usually present within the neoplasms. Extraction of DNA from tissue sections does not provide exact information about which cell population has been analysed. We present a laser microscope system that allows selective molecular analysis of single cells or small groups of cells in cases of cutaneous lymphoma.