Tumors of the diffuse endocrine system, histochemical and electron-optic aids, and pitfalls in diagnosis

Immunohistochemical reactions of primary neuroendocrine breast cancer

We performed immunohistochemical analysis of neuroendocrine breast cancer. The significance of this approach to differential diagnosis of this cancer form by detection of specific markers is demonstrated. The incidence of diagnosis of neuroendocrine breast cancer has increased 8-fold over 5 years. Neuroendocrine breast cancer is responsible for 3.4% of all breast cancer cases. The disease is significantly more incident in patients over 60. Neuroendocrine breast cancer is characterized by high expression of neuron-specific enolase (100%) and chromagranin A (57%). The data indicate that irrespective of the location, macroscopic picture, and immunohistochemical profile of cytokeratins and steroid hormones, breast cancer is characterized by clear-cut expression of neuroendocrine markers in different combinations. Immunohistochemical detection of these markers makes it possible to detect the hormone-secreting elements and evaluate their role in the tumor pool, which is essential for the differential diagnosis of neuroendocrine breast cancer, including studies of puncture biopsy specimens.

Tissue microarray analysis of neuroendocrine differentiation and its prognostic significance in breast cancer

The aim of this study was to detect neuroendocrine differentiation (NE), to determine its association with major clinicopathological parameters of breast cancer, and to study the prognostic significance of NE differentiation in a group of breast carcinomas by using tissue microarray (TMA) methodology. NE differentiation was studied by using 3 markers, synaptophysin (Syn), chromogranin A (ChA), and neuron-specific enolase (NSE) in a group of 334 patients with breast carcinoma. TMA blocks were made by using duplicate 0.6-mm-diameter tissue cores from each paraffin block. Results of immunostaining were scored on a 4-point scale, that is, as negative, weak, intermediate, and strong immunoreactivity. Positive staining of breast cancers for any of the 3 NE markers was detected in 19.5% of cases. Expression of a single marker was present in 16.2% of cases, and expression of 2 or 3 markers in combination was detected in 3.3% of cases. There was no statistically significant correlation of NE phenotype with tumor morphology, except mucinous carcinoma (3 of 6 cases positive), estrogen receptor, progesterone receptor, or nodal status. A weak correlation was noted between synaptophysin staining and higher tumor grade (P = 0.029). Analysis of disease-specific and overall survival based on up to 20 years of follow-up data showed a correlation between NSE expression and improved disease-specific (P = 0.043) and overall survival (P = 0.03) in univariate but not in multivariate analysis. The expression of Syn and ChA, as well as coexpression of multiple NE markers, had no prognostic significance.

Small cell carcinoma of the uterine corpus: CT appearance

We report a rare case of small-cell carcinoma of the uterine corpus. To our knowledge, this is the first radiological report. Computed tomography (CT) demonstrates a hypodense lesion within the endometrial cavity with nonhomogeneous contrast enhancement.

Central neural antigens: detection and diagnostic application

During the last few years, methods have been developed which permit practical use of biochemical research on the nervous system. In the central nervous system, proteins have been identified for astrocytes (glial fibrillary acidic protein and vimentin) and oligodendroglia (myelin basic protein and other glycoproteins). For certain classes of nerve cells, the neurofilament proteins and neuron-specific enolase (a glycolytic isoenzyme) have been identified. Detection of some of these substances in body fluids is possible via radioimmunoassays (RIA) and in tissue sections using the peroxidase-antiperoxidase immunohistochemical method.