Quantitative histopathological assessment of retardation of islets of langerhans degeneration in rosiglitazone-dosed obese ZDF rats using combined insulin and collagens (I and III) immunohistochemistry with automated image analysis and statistical modeling

Effects of tissue decalcification on the quantification of breast cancer biomarkers by digital image analysis

Background

Recent technical advances in digital image capture and analysis greatly improve the measurement of protein expression in tissues. Breast cancer biomarkers provide a unique opportunity to utilize digital image analysis to evaluate sources of variability that are caused by the tissue preparation, in particular the decalcification treatment associated with the analysis of bone metastatic breast cancer, and to develop methods for comparison of digital data and categorical scores rendered by pathologists.

Methods

Tissues were prospectively decalcified for up to 24 hours and stained by immunohistochemistry (IHC) for ER, PR, Ki-67 and p53. HER2 positive breast cancer sections were retrieved from the pathology archives, and annotated with the categorical HER2 expression scores from the pathology reports. Digital images were captured with Leica and Aperio slide scanners. The conversion of the digital to categorical scores was accomplished with a Gaussian mixture model and tested for accuracy by comparison to clinical scores.

Results

We observe significant effects of the decalcification treatment on common breast cancer biomarkers that are used in the clinic. ER, PR and p53 staining intensities decreased 15 – 20%, whereas Ki-67 decreased > 90% during the first 6 hrs of treatment and stabilized thereafter. In comparison with the Aperio images, pixel intensities generated by the Leica system are lower. A novel statistical model for conversion of digital to categorical scores provides a systematic approach for conversion of nuclear and membrane stains and demonstrated a high concordance with clinical scores.

Conclusion

Digital image analysis greatly improves the quantification of protein expression in human tissues. Decalcification affects the accuracy of immunohistochemical staining results and cannot be reversed by image analysis. Measurement data obtained on a continuous scoring scale can be converted to categorical scores for comparison with categorical dataset that are generated by pathologists.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_213

Electronic supplementary material

The online version of this article (doi:10.1186/s13000-014-0213-9) contains supplementary material, which is available to authorized users.

Proceedings of the 2014 National Toxicology Program Satellite Symposium

The 2014 annual National Toxicology Program (NTP) Satellite Symposium, entitled "Pathology Potpourri" was held in Washington, D.C., in advance of the Society of Toxicologic Pathology's 33rd annual meeting. The goal of this annual NTP Symposium is to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers' presentations, including diagnostic or nomenclature issues that were presented, along with select images that were used for audience voting and discussion. Some lesions and topics covered during the symposium included a pulmonary mucinous adenocarcinoma in a male B6C3F1 mouse; plexiform vasculopathy in Wistar Han (Crl:WI[Han]) rats; staging of the estrous cycle in rats and mice; peri-islet fibrosis, hemorrhage, lobular atrophy and inflammation in male Sprague-Dawley (SD) rats; retinal dysplasia in Crl:WI[Han] rats and B6C3F1 mice; multicentric lymphoma with intravascular microemboli and tumor lysis syndrome, and 2 cases of myopathy and vascular anomaly in Tg.rasH2 mice; benign thymomas in Crl:WI[Han] rats; angiomatous lesions in the mesenteric lymph nodes of Crl:WI[Han] rats; an unusual foveal lesion in a cynomolgous monkey; and finally a series of nomenclatures challenges from the endocrine International Harmonization of Nomenclature and Diagnostic Criteria (INHAND) Organ Working Group (OWG).

Morphological analysis of the pancreas and liver in diabetic KK-Aymice treated with zinc and oxovanadium complexes

Pathological conditions for type 2 diabetes mellitus in mice are recovered after treatment with a Zn²⁺complex in terms of histology of organs.