Margaret M. Grimes

The separation of benign and malignant mesothelial proliferations

The separation of benign from malignant mesothelial proliferations has emerged as a major problem in the pathology of the serosal membranes. For both epithelial and spindle cell mesothelial processes, true stromal invasion is the most accurate indicator of malignancy, but stromal invasion is often difficult to assess, especially in small biopsies. In the pleural cavity, deep penetration of a thickened and fibrotic pleura or penetration of mesothelial cells into the fat of the chest wall are good indicators of malignancy; however, superficial entrapment of mesothelial cells and glands by organizing effusions is common in benign reactions and needs to be distinguished from invasion. In the peritoneal cavity, invasion of fat or of organ walls is again the most reliable indicator of malignancy, but entrapment of benign cells in organizing granulation tissue or between fat lobules is frequent and confusing. Proliferations confined to the pleural or peritoneal space, particularly linear arrays of atypical mesothelial cells on the free surface, should not be called malignant in the absence of unequivocal invasion. Cytologic atypia is often not helpful in separating benign from malignant reactions, because benign processes are commonly atypical and mesotheliomas are often deceptively monotonous. Densely packed mesothelial cells within the pleural space are frequent in benign reactions, but densely packed mesothelial cells within the stroma favor a diagnosis of malignancy. Organizing effusions (fibrous pleurisy) typically show zonation with high cellularity and cytologic atypia toward the pleural space and increasing fibrosis with decreasing cellularity and lesser atypia toward the chest wall, whereas sarcomatous (including desmoplastic) mesotheliomas do not demonstrate this type of zonation. Elongated capillaries perpendicular to the pleural surface are seen in organizing effusions but are not a feature of sarcomatous mesotheliomas. The combination of a paucicellular storiform pattern, plus invasion of the stroma (including fat and adjacent tissues), or bland necrosis, overtly sarcomatous foci, or distant metastases, is required for the diagnosis of desmoplastic mesothelioma. Necrosis is usually a sign of malignancy but is occasionally seen in benign mesothelial reactions. Keratin staining is useful in indicating the distribution of mesothelial cells, and particularly in demonstrating penetration of mesothelial cells into the stroma or adjacent structures, but is of no help in separating benign and malignant proliferations because both are keratin-positive. Although both p53 and EMA staining have been proposed as markers of mesothelial malignancy, in our experience they are not helpful for the individual case.

Localized malignant mesothelioma

Localized malignant mesotheliomas are uncommon sharply circumscribed tumors of the serosal membranes with the microscopic appearance of diffuse malignant mesothelioma but without any evidence of diffuse spread. Little is known about their behavior. We report 23 new cases. The mean age at presentation was 63 years, and the sex ratio was approximately 2:1 (male/female). Twenty-one tumors were pleural and 2 were peritoneal. Sixteen tumors reproduced microscopic patterns of diffuse epithelial mesotheliomas, 6 had mixed epithelial and sarcomatous patterns, and 1 was purely sarcomatous. After surgical excision of the tumor, 10 of 21 patients with follow-up data were alive without evidence of disease from 18 months to 11 years after diagnosis. Patients who died had developed local recurrences and metastases, but none had diffuse pleural spread. Localized malignant mesotheliomas should be separated from diffuse malignant mesotheliomas because of their localized presentation, quite different biologic behavior, and far better prognosis.

A signature of immune function genes associated with recurrence-free survival in breast cancer patients

The clinical significance of tumor-infiltrating immune cells has been reported in a variety of human carcinomas including breast cancer. However, molecular signature of tumor-infiltrating immune cells and their prognostic value in breast cancer patients remain elusive. We hypothesized that a distinct network of immune function genes at the tumor site can predict a low risk versus high risk of distant relapse in breast cancer patients regardless of the status of ER, PR, or HER-2/neu in their tumors. We conducted retrospective studies in a diverse cohort of breast cancer patients with a 1–5xa0year tumor relapse versus those with up to 7xa0years relapse-free survival. The RNAs were extracted from the frozen tumor specimens at the time of diagnosis and subjected to microarray analysis and real-time RT-PCR. Paraffin-embedded tissues were also subjected to immunohistochemistry staining. We determined that a network of immune function genes involved in B cell development, interferon signaling associated with allograft rejection and autoimmune reaction, antigen presentation pathway, and cross talk between adaptive and innate immune responses were exclusively upregulated in patients with relapse-free survival. Among the 299 genes, five genes which included B cell response genes were found to predict with >85% accuracy relapse-free survival. Real-time RT-PCR confirmed the 5-gene prognostic signature that was distinct from an FDA-cleared 70-gene signature of MammaPrint panel and from the Oncotype DX recurrence score assay panel. These data suggest that neoadjuvant immunotherapy in patients with high risk of relapse may reduce tumor recurrence by inducing the immune function genes.

Adequacy of pathology resident training for employment: a survey report from the Future of Pathology Task Group.

CONTEXTnThe recent change in accreditation requirements for anatomic pathology and clinical pathology residency training from 5 to 4 years and the rapid advances in technologies for pathology services have sparked a renewed debate over the adequacy of pathology residency training. In particular, perceived deficiencies in training have been declared from a variety of sources, both in the form of recent editorial opinions and from surveys of community hospital pathologist employers in 1998, 2003, and 2005 by Dr Richard Horowitz.nnnOBJECTIVEnTo obtain more comprehensive data on the perceptions of strengths and weaknesses in pathology residency training.nnnDESIGNnThe College of American Pathologists conducted a survey of potential pathology employers (senior College of American Pathologists members, members designated as head of group, and members of the Association of Directors of Anatomic and Surgical Pathology). Also surveyed were recent graduates of pathology residency programs, who were identified as being junior members of the College of American Pathologists, were recent recipients of certification from the American Board of Pathology, or were contacted through their directors of pathology residency programs.nnnRESULTSnThere were 559 employer respondents, of whom 384 were responsible for hiring and/or supervising new pathologists. There were 247 recent graduates of pathology residency training programs who responded. From the employers standpoint, the majority expressed overall satisfaction with recent graduates, but almost one third of employers indicated that new hires had a major deficiency in a critical area. Specific areas of deficiency were clinical laboratory management and judgment in ordering special stains and studies. In addition, one half of employers agreed that more guidance and support for newly trained pathologists is needed now than was required 10 years ago. Academic employers generally were more satisfied than private sector employers. Newly trained pathologists did not appear to be inappropriately overconfident in their abilities. In addition, their perceptions of those specific areas in which they are most and least prepared are very similar to the ratings provided by employers. On average, newly trained pathologists ratings of their own preparedness are highest for specific aspects of general pathology and anatomic pathology, and lowest for specific aspects of clinical pathology and administration. In selecting new pathologists, employers perceived medical knowledge and interpersonal skills as the most important discriminating applicant characteristics. When new employees were asked why they thought they were offered their position, the discriminating qualifications cited most often were academic background and training, as well as completion of a fellowship and subspecialty training.nnnCONCLUSIONSnIt is our hope that the results of this survey can be used as input for further discussions and recommendations for training of pathology residents so as to further advance the ability of pathologists to provide quality patient care upon their graduation from training.

Neutralizing Endogenous IL-6 Renders Mast Cells of the MCT Type from Lung, but Not the MCTC Type from Skin and Lung, Susceptible to Human Recombinant IL-4-Induced Apoptosis

Human cord blood-derived mast cells undergo apoptosis upon exposure to recombinant human (rh)IL-4 and become resistant to rhIL-4-induced apoptosis when cultured in the presence of rhIL-6. The current study extends these effects of rhIL-4 to different populations of human mast cells, namely fetal liver-derived mast cells, lung-derived mast cells, and skin-derived mast cells. Endogenous production of IL-6 appears to protect fetal liver-derived mast cells and those of the MCT phenotype from rhIL-4-mediated apoptosis, because neutralization of IL-6 renders these mast cells sensitive. In contrast, mast cells of the MCTC phenotype from skin and lung were resistant to IL-4-mediated apoptosis, even after neutralization of endogenous IL-6. MCTC cells were CD124low, whereas those of the MCT cells were CD124high. These observations extend the phenotypic differences between MCT and MCTC types of human mast cells to include different functional responses to IL-4.

The Pathology Milestones and the Next Accreditation System

CONTEXTnIn the late 1990s, the Accreditation Council for Graduate Medical Education developed the Outcomes Project and the 6 general competencies with the intent to improve the outcome of graduate medical education in the United States. The competencies were used as the basis for developing learning goals and objectives and tools to evaluate residents performance. By the mid-2000s the stakeholders in resident education and the general public felt that the Outcomes Project had fallen short of expectations.nnnOBJECTIVEnTo develop a new evaluation method to track trainee progress throughout residency using benchmarks called milestones. A change in leadership at the Accreditation Council for Graduate Medical Education brought a new vision for the accreditation of training programs and a radically different approach to the evaluation of residents.nnnDATA SOURCESnThe Pathology Milestones Working Group reviewed examples of developing milestones in other specialties, the literature, and the Accreditation Council for Graduate Medical Education program requirements for pathology to develop pathology milestones. The pathology milestones are a set of objective descriptors for measuring progress in the development of competency in patient care, procedural skill sets, medical knowledge, practice-based learning and improvement, interpersonal and communication skills, professionalism, and systems-based practice.nnnCONCLUSIONSnThe milestones provide a national standard for evaluation that will be used for the assessment of all residents in Accreditation Council for Graduate Medical Education-accredited pathology training programs.

Senior pathology resident in-service examination scores correlate with outcomes of the American Board of Pathology certifying examinations.

The Resident In-Service Examination (RISE) addresses 1 area of the Accreditation Council for Graduate Medical Education Outcome Project; RISE results demonstrate progressive attainment of pathology knowledge during training. We compared RISE scores with primary pathology board certification success for residents graduating in 2008 and 2009. Overall RISE and nearly all sectional scores in anatomic and clinical pathology were significantly higher for residents passing all certifying examinations at the first attempt vs residents who failed any examination. The risk of failing increased with each lower quartile of overall RISE score, such that 34% (2009) and 54% (2008) of residents in the lowest quartile failed at least 1 certifying examination. Two thirds of graduating residents with lowest quartile scores had a similar quartile ranking in the previous RISE, identifying them as at risk. Residents passing the American Board of Pathology certifying examinations have a higher level of medical knowledge in general and specific pathology disciplines as assessed by senior RISE scores.

Danger signals and nonself entity of tumor antigen are both required for eliciting effective immune responses against HER-2/neu positive mammary carcinoma: implications for vaccine design.

Using parental FVB mice and their neu transgenic counterparts, FVBN202, we showed for the first time that dangerous hyperplasia of mammary epithelial cells coincided with breaking immunological tolerance to the neu “self” tumor antigen, though such immune responses failed to prevent formation of spontaneous neu-overexpressing mammary carcinoma (MMC) or reject transplanted MMC in FVBN202 mice. On the other hand, neu-specific immune responses appeared to be effective against MMC in parental FVB mice because of the fact that rat neu protein was seen as “nonself” antigen in these animals and the protein was dangerously overexpressed in MMC. Interestingly, low/intermediate expression of the neu “nonself” protein in tumors induced immune responses but such immune responses failed to reject the tumor in FVB mice. Our results showed that self–nonself (SNS) entity of a tumor antigen or danger signal alone, while may equally induce an antigen-specific immune response, will not warrant the efficacy of immune responses against tumors. On the other hand, entity of antigen in the context of dangerous conditions, i.e. abnormal/dangerous overexpression of the neu nonself protein, will warrant effective anti-tumor immune responses in FVB mice. This unified “danger-SNS” model suggests focusing on identification of naturally processed cryptic or mutated epitopes, which are considered semi-nonself by the host immune system, along with novel dangerous adjuvant in vaccine design.

Tumor escape and progression of HER-2/neu negative breast cancer under immune pressure

BackgroundEmerging data from pre-clinical and clinical studies suggest that HER-2/neu-specific T cell responses could induce HER-2/neu antigen loss in the tumor cells. These data suggest that patients with HER-2/neu negative breast cancer might have had HER-2/neu positive premalignant lesions in the past that progressed to HER-2/neu negative breast cancer under HER-2/neu-specific immune pressure.MethodsWe conducted a pilot study in patients with HER-2/neu positive and HER-2/neu negative breast cancers as well as a patient with ductal carcinoma in situ (DCIS). HER-2/neu expression was determined by FISH. HER-2/neu-specific T cell responses were determined by using IFN-γ ELISA. Expression of IFN-γ Rα in the tumors was determined by immunohistochemistry analysis of paraffin-embedded tissues.ResultsWe determined that majority of (10 of 12) patients with HER-2/neu negative breast cancer had HER-2/neu-specific IFN-γ producing T cell responses which was stronger than those in patients with HER-2/neu positive tumors. Such immune responses were associated with nuclear translocation of IFN-γ Rα in their tumor cells. Patient with DCIS also showed HER-2/neu-specific T cell responses.ConclusionThese data suggest that conducting retrospective studies in patients with HER-2/neu negative breast cancers and prospective studies in patients with HER-2/neu positive DCIS can determine whether HER-2/neu negative invasive carcinomas arise from HER-2/neu positive DCIS under the immune pressure.

Proteomic identification of 14-3-3 sigma as a common component of the androgen receptor and the epidermal growth factor receptor signaling pathways of the human prostate epithelial cell line M12

The epidermal growth factor receptor and androgen receptor (AR) both play major roles in the control of prostate growth. Our hypothesis is that shared downstream components of these two signaling pathways are significant participants in androgen-independent growth. Our first objective was to identify proteins whose activation and/or expression in AR-positive prostate epithelial cells are induced by both epidermal growth factor (EGF) and dihydrotestosterone (DHT). AR expression was induced in a tumorigenic, metastatic subline of the SV40 large T-antigen immortalized human prostate epithelial subline M12 by stable transfection with human wild-type AR cDNA. These M12AR (+) cells with functional AR were treated in parallel with EGF (10u2009ng/ml) or DHT (10−8u2009M) for 24u2009h before 2D gel electrophoresis and Western immunoblotting with antiphosphotyrosine monoclonal antibody. Coomassie blue-stained spots on a 2D gel run in parallel were aligned with the phosphoproteins on the Western immunoblot, and identified by matrix-assisted laser desorption ionization/time-of-flight mass spectroscopy. The most interesting of the seven proteins that appeared to be phosphorylated by these criteria was 14-3-3 protein sigma. Protein extracted after either EGF or DHT treatment, immunoprecipitated with antiphosphotyrosine monoclonal antibody, and immunoblotted by anti-14-3-3 sigma confirmed phosphorylation of 14-3-3 sigma. Addition of either DHT or EGF to the M12AR(+) cells induced subcellular migration of 14-3-3 sigma and activated a 14-3-3 sigma reporter construct. Immunohistochemical analysis revealed nuclear localization of 14-3-3 sigma in higher Gleason grade prostate cancers relative to benign glands. These findings implicate 14-3-3 sigma in the development of human prostate cancer cells and could provide a new target for intervention in prostate cancer.