H. Helin

A digital atlas of breast histopathology: an application of web based virtual microscopy

Aims: To develop an educationally useful atlas of breast histopathology, using advanced web based virtual microscopy technology. Methods: By using a robotic microscope and software adopted and modified from the aerial and satellite imaging industry, a virtual microscopy system was developed that allows fully automated slide scanning and image distribution via the internet. More than 150 slides were scanned at high resolution with an oil immersion ×40 objective (numerical aperture, 1.3) and archived on an image server residing in a high speed university network. Results: A publicly available website was constructed, http://www.webmicroscope.net/breastatlas, which features a comprehensive virtual slide atlas of breast histopathology according to the World Health Organisation 2003 classification. Users can view any part of an entire specimen at any magnification within a standard web browser. The virtual slides are supplemented with concise textual descriptions, but can also be viewed without diagnostic information for self assessment of histopathology skills. Conclusions: Using the technology described here, it is feasible to develop clinically and educationally useful virtual microscopy applications. Web based virtual microscopy will probably become widely used at all levels in pathology teaching.

The calcium-binding protein S100P in normal and malignant human tissues.

BackgroundS100P is a Ca2+ binding protein overexpressed in a variety of cancers, and thus, has been considered a potential tumor biomarker. Very little has been studied about its normal expression and functions.MethodsWe examined S100P expression in normal human tissues by quantitative reverse transcription polymerase chain reaction and immunohistochemistry. S100P protein expression was also studied in a series of tumors, consisting of 74 ovarian, 11 pancreatic, 56 gastric, 57 colorectal, 89 breast and 193 prostate carcinomas using a novel anti-S100P monoclonal antibody.ResultsAmong the normal tissues, the highest S100P mRNA levels were observed in the placenta and esophagus. Moderate signals were also detected in the stomach, duodenum, large intestine, prostate and leukocytes. At the protein level, the highest reactions for S100P were seen in the placenta and stomach. Immunostaining of tumor specimens showed that S100P protein is expressed in all the tumor categories included in the study, being most prevalent in gastric tumors.ConclusionBased on our observations, S100P is widely expressed in both normal and malignant tissues. The high expression in some tumors suggests that it may represent a potential target molecule for future diagnostic and therapeutic applications.

Pancreatic acinar ultrastructure in human acute pancreatitis

Ultrastructural alterations in pancreatic acini from six patients operated for acute necrotizing pancreatitis are described. One of the patients suffered from biliary tract disease, the rest had excessive alcohol intake as the presumed aetiology. Areas of the pancreatic parenchyma showing oedematous inflammation in light microscopy were studied in the electron microscope. Findings in acinar cells included changes in zymogen granules and an increased autophagocytosis in addition to unspecific organelle alterations. Zymogen granules showed increase in size and number, loss or variation of electron-density and peripheral dissolution. Increased autophagic activity was indicated by several autophagic vacuoles and residual bodies. Acinar lumina were dilated showing effacement of microvilli and invaginations in the luminal plasma membrane of the acinar cells. In acinar lumina and in the interstitium fibrillar material was observed, with an increasing frequency in those areas showing severe cellular disintegration. These findings suggest: 1) an increased activity of zymogen granules, 2) an increased autophagocytosis, and 3) penetration of acinar luminal contents into the interstitium.

Membranous location of EGFR immunostaining is associated with good prognosis in renal cell carcinoma

Epidermal growth factor receptor (EGFR) is a key factor in tumorigenesis. The association between EGFR expression and prognosis in renal cell carcinoma (RCC) is not clear. In our study of 134 RCCs, the cellular location of immunostaining was evaluated and patients with EGFR-positive tumours with prominent membranous staining had a good prognosis. Their overall survival was significantly longer (P=0.004) than that of patients with either EGFR-negative tumours or with mainly cytoplasmic staining. However, further studies on the different EGFR expression patterns in RCC are needed to clarify their role in the progression of the disease.

Virtual Microscopy in Prostate Histopathology: Simultaneous Viewing of Biopsies Stained Sequentially With Hematoxylin and Eosin, and α-Methylacyl-Coenzyme A Racemase/p63 Immunohistochemistry

PURPOSE Histopathological diagnosis of small focus carcinomas in prostatic needle biopsies is often assisted by IHC. To make a definitive diagnosis the pathologist must compare IHC findings with hematoxylin and eosin stained tissue morphology. We introduce what is to our knowledge a new application of virtual microscopy, in which hematoxylin and eosin, and IHC stains done sequentially on the same microscope slide can be simultaneously displayed and compared on a computer screen. MATERIALS AND METHODS A total of 30 hematoxylin and eosin stained prostatic needle biopsies were scanned with a computer controlled microscope. The slides were destained and then immunostained with a cocktail of AMACR and p63 antibodies, which labels the nuclei of nonmalignant basal cells (p63) and the cytoplasm of neoplastic glandular cells suspicious for malignancy (AMACR). The slides were then scanned again and the pairs of virtual slides were aligned for synchronized viewing. RESULTS The presented technique was found helpful when suspicious lesions were small and when examining the immunoprofile of specimens was warranted, in addition to examining hematoxylin and eosin stained tissue morphology. The usefulness of our approach based on virtual microscopy can be evaluated on the website , which also serves as an educational tool for self-learning the correlation between hematoxylin and eosin stained tissue morphology, and AMACR/p63 IHC in prostate biopsies. CONCLUSIONS The technology for simultaneously viewing sequentially hematoxylin and eosin and IHC stained prostate biopsies can be readily used for educational purposes, as exemplified by our website, and along with the availability of rapid virtual slide scanners it can also be used for clinical diagnostics.

Discordant results between radioligand and immunohistochemical assays for steroid receptors in breast carcinoma

Surgical biopsy specimens of 179 breast carcinoma were studied by steroid-binding and immunohistochemical assays or oestrogen and progesterone receptors (ER, PR) in order to explore reasons for discordant results between the two assay types. Receptor statuses in 18% of ER assays and 30% of PR assays were in disagreement. Immunohistochemistry-positive steroid-binding-negative status predominated among the discordant ER assays, while the discordant PR assays displayed the opposite situation. In discordant assays receptor concentration was significantly more often close to the cut-off (10-50 fmol mg-1) than in the concordant ones. Low binding affinity (high Kd) was also significantly associated with disagreeing assay results. These observations clearly indicate that immunohistochemical ER and PR assays measure high-affinity binding components (i.e. type I receptors) in steroid-binding assays. ER but not PR assays in premenopausal women disagreed more often than those in post-menopausal women. Such factors as histological type, specimen size in steroid-binding assay, grade of malignancy and tumour necrosis were statistically unrelated to agreement or disagreement of receptor assays.

Immunohistochemical versus biochemical estrogen-receptor and progesterone-receptor analysis: correlation with histological parameters

SummaryHuman breast carcinomas were evaluated for estrogen and progesterone receptors by immunohistochemistry using monoclonal anti-receptor antibodies (n=267) and by cytosol steroid-binding assays (n=212). The estrogen and progesterone receptor contents of the tumors correlated with histological features of differentiation, such as histological and nuclear grade, and with the amount of tumor necrosis and lymphoid infiltration. The correlation of immunohistochemically determined steroid receptor values with histological characteristics was somewhat better than that of biochemically assessed concentrations.