Standardized mitotic counts in breast cancer. Evaluation of the method.

Twenty-one pathologists and technicians participated in a study evaluating the variation present in mitotic counts for prognostication of breast cancer. The participants counted the mitotic figures in 20 breast cancer samples from ten high power fields (mitotic activity index, MAI, giving the results in mitotic figures per 10 fields) and also made a correction for field size and area fraction of the neoplastic epithelium to get the standardized mitotic index (volume fraction corrected mitotic index, or M/VV index, giving the result in mitotic figures per square mm of neoplastic epithelium). The difference in variation between the two methods was not big, but the standardized mitotic index (SMI) showed consistently smaller variation among all participants and different subgroups. Experienced pathologists had the highest variation in mitotic counts, and specially trained technicians, the lowest. The efficiency of the mitotic counts in grading (the grading efficiency) was used to evaluate the mitotic counts. In groups without special training for mitotic counts the mean grading efficiency was lower (experienced and training pathologists both on average had the potential to grade 88% of the cases correctly) than in the group specially trained for the purpose (trained technicians had the potential to grade 95% of the cases correctly). Among the specially trained technicians, the grading efficiency was of the same magnitude as the grading efficiency achieved in determining the S-Phase fraction of cells from paraffin embedded breast cancers by flow cytometry in different laboratories. The results suggest that special training is helpful in making mitotic counts more reproducible, and that in trained hands, the mitotic counts give results comparable to more sophisticated methods of determining proliferative activity in breast cancer.

[Gastritis. Current point of view of the anatomo-pathologist]. / Les gastrites. Point de vue actuel de l'anatomo-pathologiste.

Acute, granulomatous and chronic are the three main forms of gastritis. The discovery of Helicobacter pylori has stimulated a new detailed classification of gastritis. Having set out the various conventional histopathological classifications, the authors describe two newly recognized types of gastritis, lymphocytic gastritis and reactive gastritis. The authors also recall the earlier pathogenic classifications of gastritis, first initiated by Strickland and Mackay. Because of the problems related to these earlier classifications, the "Sydney system" has been developed. This system allows to simply pathologists' reports, by incorporating the morphological, topographical and etiological parameters of gastritis. Some of the advantages and disadvantages of the "Sydney system" are briefly discussed.

Collagenous, microscopic and lymphocytic colitis. An evolving concept.

Collagenous colitis and lymphocytic colitis (previously described as microscopic colitis) are two newly recognised forms of colitis. Both have generated much controversy and continue to do so; their aetiology and pathogenesis are unresolved and their association with a variety of immune-related disorders is intriguing. Response to available therapeutic modalities is often disappointing. The possible relationship or overlap between these two conditions remains a controversial issue. The aim of this review is essentially to present an overview of collagenous colitis and lymphocytic colitis and to propose an unifying concept with an adapted terminology.

Newly recognized forms of colitis: collagenous colitis, microscopic (lymphocytic) colitis, and lymphoid follicular proctitis.

Based on pertinent data from the literature and on their personal experience, the authors present a clinicopathological review of collagenous colitis, microscopic (lymphocytic) colitis, and lymphoid follicular proctitis. The following aspects of these three newly recognized forms of colitis are emphasized: clinical features, light microscopy, histological diagnostic problems, immunological aspects, coexisting diseases, treatment, etiology, and pathogenesis. Special attention is paid to possible overlap between collagenous colitis and microscopic (lymphocytic) colitis.

Ménétrier's disease with lymphocytic gastritis: an unusual association with possible pathogenic implications.

Ménétrier's disease is a rare form of hypertrophic or hyperplastic gastropathy, characterized by conspicuous thickening of the gastric mucosal folds and foveolar (crypt) hyperplasia. The pathogenesis of Ménétrier's disease remains unresolved. Lymphocytic gastritis is a newly described entity which corresponds endoscopically to varioliform gastritis and is marked by T-lymphocyte infiltration of the surface epithelium and crypts. Five surgical cases and one autopsy case combining the gross and microscopic features of Ménétrier's disease and lymphocytic gastritis are presented. This unusual and hitherto previously undescribed association raises the possibility of a common pathogenesis for Ménétrier's disease and lymphocytic gastritis.

Apparent lack of usefulness of monoclonal antibody Ki-67 in thyroid tumour pathology. Relation to histological typing and classification.

In order to test its potential application to thyroid tumour pathology, the monoclonal antibody Ki-67 was used to demonstrate immunohistochemically proliferating cells in 31 non neoplastic and neoplastic lesions of the thyroid. Twenty benign lesions were negative. Of the 11 malignant tumors, 4 papillary, 2 follicular and 1 medullary carcinomas were also negative; only 3 follicular and 1 medullary carcinomas were positive. Moreover, no correlation was found between Ki-67 immunostaining status and histological typing or pTNM pathological classification in the 11 malignant tumors.