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Background: We conducted a large international study to estimate fractions of head and neck cancers (HNCs) attributable to human papillomavirus (HPV-AFs) using six HPV-related biomarkers of viral detection, transcription, and cellular transformation. Methods: Formalin-fixed, paraffin-embedded cancer tissues of the oral cavity (OC), pharynx, and larynx were collected from pathology archives in 29 countries. All samples were subject to histopathological evaluation, DNA quality control, and HPV-DNA detection. Samples containing HPV-DNA were further subject to HPV E6*I mRNA detection and to p16(INK4a), pRb, p53, and Cyclin D1 immunohistochemistry. Final estimates of HPV-AFs were based on HPV-DNA, HPV E6*I mRNA, and/or p16(INK4a) results. Results: A total of 3680 samples yielded valid results: 1374 pharyngeal, 1264 OC, and 1042 laryngeal cancers. HPV-AF estimates based on positivity for HPV-DNA, and for either HPV E6* I mRNA or p16(INK4a), were 22.4%, 4.4%, and 3.5% for cancers of the oropharynx, OC, and larynx, respectively, and 18.5%, 3.0%, and 1.5% when requiring simultaneous positivity for all three markers. HPV16 was largely the most common type. Estimates of HPV-AF in the oropharynx were highest in South America, Central and Eastern Europe, and Northern Europe, and lowest in Southern Europe. Women showed higher HPV-AFs than men for cancers of the oropharynx in Europe and for the larynx in Central-South America. Conclusions: HPV contribution to HNCs is substantial but highly heterogeneous by cancer site, region, and sex. This study, the largest exploring HPV attribution in HNCs, confirms the important role of HPVs in oropharyngeal cancer and drastically downplays the previously reported involvement of HPVs in the other HNCs.

Introduction Leiomyoma with bizarre nuclei (LBN) and cellular leiomyoma (CL) are rare variants of uterine smooth muscle tumors. In diagnostic practice, LBN can be mistaken for leiomyosarcoma (LMS), while CL may mimic low grade endometrial stromal sarcoma (LG ESS). Careful evaluation of morphological features is necessary when making the diagnosis; in some borderline cases, immunohistochemical and molecular examinations may help. Literature data on molecular genetic alterations in LBN and CL is limited, but some of these tumors appear to share certain aberrations with classical leiomyomas (UL) and LMS. Aims The aim of the work is to expand the knowledge about smooth muscle tumors of the uterus, especially LBN and CL, and perform a complex morphological, immunohistochemical (IHC), and molecular evaluation of their features. The individual goals include: 1) confirmation of the hypothesized benign behaviour of LBN, 2) morphological analysis of LBN, 3) more detailed clarification of LBN tumorigenesis with a focus on the FH gene, 4) clarification of CL tumorigenesis, 5) the use of IHC FH antibody as a screening method to identify FH gene mutations, 6) the use of morphological evaluation and results of IHC examination to facilitate differential diagnostic balance between benign and malignant smooth muscle...

This doctoral thesis deals with morphological and immunohistochemical analysis of melanocytic lesions. Melanoma is the most dangerous malignant skin tumor with its potential occurrence outside the skin. Its early diagnosis is the basic aspect of a favorable disease prognosis. Distant metastases development occurring several years after the initial diagnosis is a typical feature of melanoma. Histopathological differential diagnostics of melanocytic lesions is extremely difficult because of the diversity of melanocytic lesions. Contemporary research is focused on the identification of new surrogate markers based on immunohistochemistry or molecular genetics, which would be enable to estimate the behavior of a certain lesion and clarify the gray zone of melanocytic lesions of uncertain biological behavior. The doctoral thesis is focused on the immunohistochemical analysis of GLUT-1 protein expression in 400 cases of benign and malignant melanocytic lesions. Significant expression of this marker was identified in the group of melanomas, it was not identified in melanocytic nevi. Expression of GLUT-1 corresponded to the worse prognosis of the disease. The doctoral thesis also deals with the issue of TILs. The analysis of TILs (tumor infiltrating lymphocytes) in 213 melanomas compared the prognostic...

Introduction HNF1B is a tissue-specific transcription factor, which plays a crucial role in the embryological development of a number of organs, especially kidneys, gastrointestinal system, pancreas and billiary system. While the significance of HNF1B in the development of urinary tract malformations has already been well described, its role in the pathogenesis of solid tumors has not yet been elucidated. Based on the current data it seems that depending on the type of individual tumor HNF1B can either act as an oncogene or a tumor suppressor. However, the precise mechanism of how it exerts its influence is still unclear. Aims: The thesis focuses on expanding the knowledge of the significance of HNF1B changes in selected solid tumors and non-neoplastic lesions. The individual goals include: 1) determining the role which HNF1B plays in the pathogenesis of these lesions, 2) evaluating the significance of HNF1B for differential diagnosis, 3) analysis of the prognostic and predictive meaning of HNF1B, 4) mutation analysis of the HNF1B gene in all the tumor and non-tumor tissues with the aim to identify novel pathogenic mutations, 5) methylation analysis of the HNF1B promoter. Material and methods: Immunohistochemical examination with the antibody against HNF1B was performed on 516 samples of tumor and...