DNA methylation profiling of salivary gland tumors supports and expands conventional classification.

Tumors of the major and minor salivary gland histologically encompass a diverse and partly overlapping spectrum of frequently diagnostically challenging neoplasms. Despite recent advances in molecular testing and the identification of tumor-specific mutations or gene fusions, there is an unmet need to identify additional diagnostic biomarkers for entities lacking specific alterations. In this study, we collected a comprehensive cohort of 363 cases encompassing 20 different salivary gland tumor entities and explored the potential of DNA methylation to classify these tumors. We were able to show that most entities show specific epigenetic signatures and present a machine learning algorithm that achieved a mean balanced accuracy of 0.991. Of note, we showed that cribriform adenocarcinoma is epigenetically distinct from classical polymorphous adenocarcinoma, which could support risk stratification of these tumors. Myoepithelioma and pleomorphic adenoma form a uniform epigenetic class, supporting the theory of a single entity with a broad but continuous morphological spectrum. Furthermore, we identified a histomorphologically heterogeneous but epigenetically distinct class that could represent a novel tumor entity. In conclusion, our study provides a comprehensive resource of the DNA methylation landscape of salivary gland tumors. Our data provides novel insight into disputed entities and shows the potential of DNA methylation to identify new tumor classes. Furthermore, in future, our machine learning classifier could support the histopathological diagnosis of salivary gland tumors.

Transanal total mesorectal excision for restorative coloproctectomy in an obese high-risk patient with colitis-associated carcinoma.

Transanal total mesorectal excision (TaTME) offers great potential for the treatment of malign and benign diseases. However, laparoscopic-assisted TaTME in ulcerative colitis has not been described in more than a handful of patients. We present a 47-year-old highly comorbid female patient with an ulcerative colitis-associated carcinoma of the ascending colon and steroid- refractory pancolitis. A two-stage restorative coloproctectomy including right-sided complete mesocolic excision was conducted. The second step consisted of a successful nerve-sparing TaTME and a handsewn ileal pouch-anal anastomosis. TaTME may extend the possible treatment options in inflammatory bowel disease, especially for high-risk patients.

The Role of the Immune Phenotype in Tumor Progression and Prognosis of Patients with Mycosis Fungoides: A Quantitative Immunohistology Whole Slide Approach.

BACKGROUND AND OBJECTIVES: Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphomas, characterized by mature, skin-tropic CD4+ T-helper cells. In order to study the immune tumor microenvironment in MF patients, we performed immunohistochemical stains on MF biopsies, digitized whole-slide tissue sections, and performed quantitative analysis of the different immune cell subsets to correlate tissue parameters with the clinical data of patients, such as progression-free survival or overall survival. PATIENTS AND METHODS: Overall, 35 patients who were treated between 2009 and 2019 and for whom one or more paraffin tissue blocks were available have been included in the present study (58 tissue specimens in total). Conventional immunohistochemistry stains for CD3, CD4, CD8, CD20 and CD30 were used for the analysis of the immune phenotype, and quantitative analysis was performed using QuPath as a quantitative digital pathology tool for bioimage analysis of whole slides. RESULTS: Analysis of tissue parameters for prognostic significance revealed that patients with a stronger infiltration by CD8+ lymphocytes within the tumor cell compartment had a higher risk of disease progression (p = 0.031) and showed a shorter progress-free survival (p = 0.038). Furthermore, a significant association of the percentage of CD30+ cells (median: 7.8%) with the risk of disease progression (p = 0.023) and progression-free survival (p = 0.023) was found. In relation to the clinical features of our patient cohort, a higher risk of disease progression (p = 0.015) and a shorter progression-free survival (p = 0.032) for older patients (>61 years) were observed. CONCLUSIONS: Our results demonstrated the prognostic relevance of large-cell transformation in mycosis fungoides and its strong association with the presence of CD30+ lymphocytes. Unlike previous reports, our study suggests an adverse prognostic role for CD8+ T cells in patients with mycosis fungoides. Moreover, our data indicate that the immune phenotype within the tumor microenvironment shows strong temporal heterogeneity and is altered in the course of tumor progression.

Artificial Intelligence in Pathology.

BACKGROUND: Increasing digitalization enables the use of artificial intelligence (AI) and machine learning in pathology. However, these technologies have only just begun to be implemented, and no randomized prospective trials have yet shown a benefit of AI-based diagnosis. In this review, we present current concepts, illustrate them with examples from representative publications, and discuss the possibilities and limitations of their use. METHODS: This article is based on the results of a search in PubMed for articles published between January 1950 and January 2020 containing the searching terms "artificial intelligence," "deep learning," and "digital pathology," as well as the authors' own research findings. RESULTS: Current research on AI in pathology focuses on supporting routine diagnosis and on prognostication, particularly for patients with cancer. Initial data indicate that pathologists can arrive at a diagnosis faster and more accurately with the aid of a computer. In a pilot study on the diagnosis of breast cancer, involving 70 patients, sensitivity for the detection of micrometastases rose from 83.3% (by a pathologist alone) to 91.2% (by a pathologist combined with a computer algorithm). The evidence likewise suggests that AI applied to histomorphological properties of cells during microscopy may enable the inference of certain genetic properties, such as mutations in key genes and deoxyribonucleic acid (DNA) methylation profiles. CONCLUSION: Initial proof-of-concept studies for AI in pathology are now available. Randomized, prospective studies are now needed so that these early findings can be confirmed or falsified.

Lamin-B1 is a senescence-associated biomarker in clear-cell renal cell carcinoma.

Clear-cell renal cell carcinoma (ccRCC) is a von-Hippel-Lindau gene (VHL) associated tumor disease. In addition to activating the hypoxia inducible factor (HIF) dependent oxygen-sensing pathway, VHL loss also has an impact on a HIF-independent senescence program which functions as a tumorigenesis barrier. Lamin-B1 is a nuclear intermediate filament protein that exhibits effects on chromatin structure and gene expression and acts as a senescence effector. In the present study, the expression and prognostic relevance of Lamin-B1 in a large cohort of ccRCC patients was examined and the report presents initial functional data on possible therapeutic implications. The expression of Lamin-B1 was measured by immunohistochemistry using a tissue microarray containing tumor tissue samples from 763 ccRCC patients. Chi-squared tests, Kaplan-Meier curves and Cox regression models were used to investigate the possible association between Lamin-B1 expression, clinical and pathological characteristics and patient survival. High Lamin-B1 expression was associated with poor clinical outcomes and multivariate Cox regression analyses revealed that Lamin-B1 was an independent prognostic factor for cancer-specific survival. Furthermore in vitro data suggested that Lamin-B1 acted as a functional downstream senescence effector in RCC cell lines. In conclusion, patients affected by ccRCC with high Lamin-B1 expression exhibit poor prognosis. Lamin-B1 may serve as a tissue-based biomarker for new therapeutic agents targeting therapy-induced senescence.