Pathology without microscope: From a projection screen to a virtual slide.

We have witnessed successive stages since the Seventies in the advancements towards digital pathology. We agree with Dr Pallua et al on the tremendous changes that are taking place in pathology, all leading toward greater role of digitalization in the field of pathology, both in terms of consultation and teaching. In particular, distance teaching using digital pathology will grow into a mainstream mode of pathology teaching, something that has been reinforced by COVID-19.

Epigenetic modulations and lineage plasticity in advanced prostate cancer.

Prostate cancer is the most common cancer and second leading cause of cancer-related death in American men. Antiandrogen therapies are part of the standard of therapeutic regimen for advanced or metastatic prostate cancers; however, patients who receive these treatments are more likely to develop castration-resistant prostate cancer (CRPC) or neuroendocrine prostate cancer (NEPC). In the development of CRPC or NEPC, numerous genetic signaling pathways have been under preclinical investigations and in clinical trials. Accumulated evidence shows that DNA methylation, chromatin integrity, and accessibility for transcriptional regulation still play key roles in prostate cancer initiation and progression. Better understanding of how epigenetic change regulates the progression of prostate cancer and the interaction between epigenetic and genetic modulators driving NEPC may help develop a better risk stratification and more effective treatment regimens for prostate cancer patients.

Focal laser ablation as clinical treatment of prostate cancer: report from a Delphi consensus project.

PURPOSE: To define the role of focal laser ablation (FLA) as clinical treatment of prostate cancer (PCa) using the Delphi consensus method. METHODS: A panel of international experts in the field of focal therapy (FT) in PCa conducted a collaborative consensus project using the Delphi method. Experts were invited to online questionnaires focusing on patient selection and treatment of PCa with FLA during four subsequent rounds. After each round, outcomes were displayed, and questionnaires were modified based on the comments provided by panelists. Results were finalized and discussed during face-to-face meetings. RESULTS: Thirty-seven experts agreed to participate, and consensus was achieved on 39/43 topics. Clinically significant PCa (csPCa) was defined as any volume Grade Group 2 [Gleason score (GS) 3+4]. Focal therapy was specified as treatment of all csPCa and can be considered primary treatment as an alternative to radical treatment in carefully selected patients. In patients with intermediate-risk PCa (GS 3+4) as well as patients with MRI-visible and biopsy-confirmed local recurrence, FLA is optimal for targeted ablation of a specific magnetic resonance imaging (MRI)-visible focus. However, FLA should not be applied to candidates for active surveillance and close follow-up is required. Suitability for FLA is based on tumor volume, location to vital structures, GS, MRI-visibility, and biopsy confirmation. CONCLUSION: Focal laser ablation is a promising technique for treatment of clinically localized PCa and should ideally be performed within approved clinical trials. So far, only few studies have reported on FLA and further validation with longer follow-up is mandatory before widespread clinical implementation is justified.

Italian prostate biopsies group: 2016 updated guidelines insights

AIM: To present a summary of the updated guidelines of the Italian Prostate Biopsies Group following the best recent evidence of the literature. MATERIALS AND METHODS: A systematic review of the new data emerging from 2012-2015 was performed by a panel of 14 selected Italian experts in urology, pathology and radiology. The experts collected articles published in the English-language literature by performing a search using Medline, EMBASE and the Cochrane Library database. The articles were evaluated using a systematic weighting and grading of the level of the evidence according to the Grading of Recommendations Assessment, Development and Evaluation framework system. RESULTS: An initial prostate biopsy is strongly recommended when i) prostate specific antigen (PSA) >10 ng/ml, ii) digital rectal examination is abnormal, iii) multiparametric magnetic resonance imaging (mpMRI) has a Prostate Imaging Reporting and Data System (PIRADS) ≥4, even if it is not recommended. The use of mpMRI is strongly recommended only in patients with previous negative biopsy. At least 12 cores should be taken in each patient plus targeted (fusion or cognitive) biopsies of suspicious area (at mpMRI or transrectal ultrasound). Saturation biopsies are optional in all settings. The optimal strategy for reducing infection complications is still a controversial topic and the instruments to reduce them are actually weak. The adoption of Gleason grade groups in adjunction to the Gleason score when reporting prostate biopsy results is advisable. CONCLUSION: These updated guidelines and recommendations are intended to assist physicians and patients in the decision-making regarding when and how to perform a prostatic biopsy.

New toxicity profile for novel immunotherapy agents: focus on immune-checkpoint inhibitors.

INTRODUCTION: Tumor development results from a cancer-induced immunosuppression (immune-editing). Immunotherapy has revolutionized the treatment paradigm for many malignancies, putting clinicians before novel toxicities, of immune-mediated etiology (immune-related adverse events). AREAS COVERED: Immune-mediated toxicity depends on both innate and adaptive immunity mechanisms. Healthy tissue damage depends on an aspecific T-cell hyperactivation response causing cross-reaction with normal tissues, which leads to an overproduction of CD4 T-helper cell cytokines and an abnormal migration of cytolytic CD8 T-cells. By stimulating a diffuse T-cell repertoire expansion, immune-checkpoint inhibitors counteract tumor growth but reduce the self-tolerance, damaging healthy organs. In this review, we summarize the toxicity profile of the novel immune-checkpoint inhibitors and their clinical implications, we are convinced that a deep understanding and a prompt resolution of the paradigmatic toxicities of these drugs will result in clinical benefits to patients and an enhanced antitumor effect. EXPERT OPINION: A focus on immunotoxicity is important in the education of clinicians and will improve patient safety. There is a willingness to tailor specific immune-therapies to each cancer patient, and to stimulate researchers through understanding of the physiopathogenesis, using the hypothesis that immune-mediated toxicities can be used as predictors of response or a prognostic sign of survival, thereby guiding therapeutic decisions.

PD-1 blockade therapy in renal cell carcinoma: current studies and future promises.

RCC is considered an immunogenic tumor with a prominent dysfunctional immune cell infiltrate, unable to control tumor growth. Evasion of immune surveillance, a process defined immune-editing, leads to malignant progression. The striking improvement of knowledge in immunology has led to the identification of immune checkpoints (such as CTLA-4 and PD-1), whose blockage enhances the antitumor immunity. The interaction between PD-1, an inducible inhibitory receptor expressed on lymphocytes and DCs, and PD-L1 ligand, expressed by tumor cells, results in a down-regulation of the T-cell response. Therefore, the PD-1/PD-L1 axis inhibition by targeted-antibodies, increasing the T-cell proliferation and cytotoxicity, represents a promising mechanism to stimulate the anti-tumor activity of the immune system, improving the outcomes of cancer patients. Several PD-1 and PD-L1 inhibitors have been evaluated in different tumor types, showing promising results. The interesting correlation between lymphocytes PD-1 expression and RCC advanced stage, grade and prognosis, as well as the selective PD-L1 expression by RCC tumor cells and its potential association with worse clinical outcomes, have led to the development of new anti PD-1/PD-L1 agents, alone or in combination with anti-angiogenic drugs or other immunotherapeutic approaches, for the treatment of RCC. In this review we discuss the role of PD-1/PD-L1 in RCC, focusing on the biological rationale, current clinical studies and promising therapeutic perspectives to target the PD-1 pathway.

[Vancouver classification of renal tumors: Recommendations of the 2012 consensus conference of the International Society of Urological Pathology (ISUP)]. / Vancouver-Klassifikation von Nierentumoren : Empfehlungen der Konsenskonferenz der Internationalen Gesellschaft für Uropathologie (ISUP) 2012.

The 2012 consensus conference of the International Society of Urological Pathology (ISUP) has formulated recommendations on classification, prognostic factors and staging as well as immunohistochemistry and molecular pathology of renal tumors. Agreement was reached on the recognition of five new tumor entities: tubulocystic renal cell carcinoma (RCC), acquired cystic kidney disease-associated RCC, clear cell (tubulo) papillary RCC, microphthalmia transcription factor family RCC, in particular t(6;11) RCC and hereditary leiomyomatosis-associated RCC. In addition three rare forms of carcinoma were considered as emerging or provisional entities: thyroid-like follicular RCC, succinate dehydrogenase B deficiency-associated RCC and anaplastic lymphoma kinase (ALK) translocation RCC. In the new ISUP Vancouver classification, modifications to the existing 2004 World Health Organization (WHO) specifications are also suggested. Tumor morphology, a differentiation between sarcomatoid and rhabdoid and tumor necrosis were emphasized as being significant prognostic parameters for RCC. The consensus ISUP grading system assigns clear cell and papillary RCCs to grades 1-3 due to nucleolar prominence and grade 4 is reserved for cases with extreme nuclear pleomorphism, sarcomatoid and/or rhabdoid differentiation. Furthermore, consensus guidelines were established for the preparation of samples. For example, agreement was also reached that renal sinus invasion is diagnosed when the tumor is in direct contact with the fatty tissue or loose connective tissue of the sinus (intrarenal peripelvic fat) or when endothelialized cavities within the renal sinus are invaded by the tumor, independent of the size. The importance of biomarkers for the diagnostics or prognosis of renal tumors was also emphasized and marker profiles were formulated for use in specific differential diagnostics.

Variation in reporting of cancer extent and benign histology in prostate biopsies among European pathologists.

It is not known how uropathologists currently report histopathological features of prostate biopsies such as core length, tumor extent, perineural invasion, and non-tumor-associated features such as inflammation and hyperplasia in needle biopsies. A web-based survey was distributed among 661 members of the European Network of Uropathology. Complete replies were received from 266 pathologists in 22 European countries. Total core lengths were reported by 64 %. The numbers of cores positive for cancer was given by 79 %. Linear cancer extent was reported by 81 %, most often given in millimeters for each core (53 %) followed by the estimation of percentage of cancer in each core (40 %). A gap of benign tissue between separate cancer foci in a single core would always be subtracted by 48 % and by 63 % if cancer foci were minute and widely separated. Perineural invasion was reported by 97 %. Fat invasion by tumor was interpreted as extraprostatic extension by 81 %. Chronic and active/acute inflammation was always reported by 32 and 56 % but only if pronounced by 54 and 39 %, respectively. While most (79 %) would never diagnose benign prostatic hyperplasia on needle biopsy, 21 % would attempt to make this diagnosis. Reporting practices for prostate biopsies are variable among European pathologists. The great variation in some methodologies used suggests a need for further international consensus, in order for retrospective data to be comparable between different institutions.

Reproducibility of histopathologic tumor grading in penile cancer--results of a European project.

Since reliable molecular prognostic parameters for inguinal lymph metastases in penile cancer are not available, tumor grading is often used as a surrogate prognostic tool for the indication of inguinal lymphadenctomy and has been integrated into the current TNM classification for penile cancer. The reliability of tumor grading is under discussion. We examined interobserver grading variability in 90 primary penile carcinomas, assessed by 12 different uropathologists from five European countries. Tumor grading, following the CAP scheme, was compared, and interobserver variability was calculated using kappa statistics. The interobserver variability was high as reflected by an overall low kappa coefficient (mean k = 0.34) and reached a moderate level only in 26.4 % of the cases (range 0.02-0.67). The percentage of G1 tumors assigned ranged from 8.6 to 52.5 %, G2 tumors from 27.1 to 72.6 % and G3 tumors from 11.7 to 48.7 %. Only some observers assigned G4 with a range of 0.6-21.9 %. Subdivision into low and high grade according to UICC and EAU classifications differed significantly (P < 0.001). Low reproducibility of grading in penile carcinomas with the favored method does not allow a reliable prognostication of tumor aggressiveness. Inclusion of histological grading into the TNM classification currently seems not to be a benefit.

Targeting prostate-specific membrane antigen for personalized therapies in prostate cancer: morphologic and molecular backgrounds and future promises.

Prostate-specific membrane antigen (PSMA) is an integral, non-shed membrane glycoprotein that is highly expressed on prostate epithelial cells and strongly upregulated in prostate cancer (PCa). Prostatic neoplastic transformation results in the transfer of PSMA from the apical membrane to the luminal surface of the ducts. However, the role of PSMA in tumor angiogenesis and carcinogenesis is poorly understood. PSMA is characterized by folate hydrolase and carboxypeptidase activity and internalization function, and its levels are directly correlated to androgen independence, metastasis and PCa progression. As largely substantiated by preclinical and clinical findings, PSMA could represent a promising target for Positron Emission Tomography (PET) radiopharmaceuticals for PCa imaging. Furthermore, PSMA could prove an important target for the development of new therapeutic approaches, including PSMA-based aptamers, peptides, antibody-drug conjugated therapy, as well as radiotherapy and immunotherapy. This review will summarize the role of PSMA in PCa development and progression and its potential role in the diagnosis and treatment of patients with initial and advanced PCa.

Pathology of upper tract urothelial carcinoma with emphasis on staging.

Classification of upper tract urothelial preneoplastic and neoplastic lesions mirrors that of the urinary bladder, with all lesions of the bladder urothelium being possible in the upper tract and vice versa. There are three major groups of non-invasive urothelial neoplasms: flat, papillary, and inverted. These three groups share a similar morphological spectrum of intraurothelial changes, ranging from hyperplasia to dysplasia to carcinoma in situ. However, they differ in terms of architectural growth pattern compared to the surrounding non-neoplastic mucosal surface. Infiltrating urothelial carcinoma is defined as a urothelial tumor that invades beyond the basement membrane. Unlike in non-invasive papillary urothelial neoplasms (pTa), the role of histologic grade in pT1 and higher stage tumors has been suggested to be of only relative importance. The vast majority of tumors of the upper urinary tract are urothelial carcinoma. More commonly seen, however, are foci of squamous differentiation and, less frequently, glandular differentiation. Pure urothelial carcinomas also display a wide range of variant morphologies, and recognition of these morphologies is important for diagnosis, classification, and prognosis.

Karyometry and quantitative immunohistochemical analysis of the urothelium in tissue sections: a feasibility study based on chromatin remodeler DAXX immunostaining.

The aim of this study was to investigate the feasibility of applying a software traditionally used in the field of engineering to pathology, in particular to tissue sections from normal urothelium (NU) immuno-stained for the chromatin remodeler DAXX (death domain-associated protein). The study included 5 cases of NU. Images were recorded with a Nikon digital camera. The nuclear area and the intensity of nuclear staining were analyzed with a software package developed in LabVIEW environment. The nuclear size is 14.8 plus or minus 6.5 square microns. The nuclei in the cells adjacent to the stroma are slightly smaller than in the intermediate cells by a factor of 0.86. The mean nuclear area of the nuclei in the superficial cell layer in NU is identical to the nuclei in the intermediate cell layers. For each nucleus intensity of nuclear staining is calculated based on the gray value of the individual picture elements in the green color plane. The mean and standard deviation of nuclear gray value are 106 plus or minus 15. The mean value in the nuclei adjacent to the stroma is slightly greater by a factor 1.02 and 1.04 compared to the intermediate and superficial cell layers. In conclusion, this exploratory study shows that karyometry and quantitative immunohistochemical analysis can be done accurately by using a digital camera commonly available to pathologists and an image analysis software routinely used in the field of engineering.

Fluorescence in situ hybridization analysis of CCND3 gene as marker of progression in bladder carcinoma.

The aim of this study was to assess patterns of CCND3 gene amplification in bladder cancer and correlate gene status with recurrence-free and progression-free survival. A sequential cohort series of 102 primary bladder tumor samples in which there was enough tissue material to assess CCND3 gene status by fluorescent in situ hybridization (FISH) was the study group. CCND3 gene FISH amplification present in 31.4 percent of bladder carcinomas, was related to tumor progression (p=0.021) and lower time to progression (mean+-SD; 25.75+-15.25 months) as compared to 33.29+-11.0 months in the CCND3 not amplified group (p=0.05). By immunohistochemistry, Cyclin D3 labeling index was higher in the CCND3 amplified group (mean+-SD, 76.69+-27.51) than in not amplified (mean+-SD, 21.57+-7.02) (p less than 0.0001). The univariate survival analysis showed CCND3 gene amplification to be associated to a shorter progression-free survival (p=0.020) together with WHO histological grade (p=0.001) and pT stage category (p less than 0.0001). Cox’s regression analysis selected CCND3 amplification as an independent predictor of progression-free survival (p= 0.030, RR3.561, 95 percent CI 1.128-11.236) together with pT category (p less than 0.0001, RR5.834, 95 percent CI 2.364-14.395). Our FISH analysis suggests that CCND3 gene amplification is a marker of aggressiveness and might be a predictor of tumor progression in bladder urothelial carcinoma.

Update on selected renal cell tumors with clear cell features. With emphasis on multilocular cystic clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (CCRCC) is the most common malignant tumor of renal epithelial origin and, with the exception of some rare tumors, the most deadly. The exception is represented by the multilocular cystic CCRCC, whose prognosis is excellent with survival rates of 100% when diagnosis is made according to the WHO definition. For this reason a proposal has been made to rename this tumor as multilocular cystic renal cell neoplasms of low malignant potential. Another exemption could be the clear cell (tubulo) papillary renal cell carcinoma/clear cell papillary renal cell carcinoma (CCPRCC), a tumor with tubulopapillary architecture and clear cytoplasm. Published data indicates that these are neoplasms with indolent clinical behavior. No cases with metastasis have been reported. Neoplasms meeting criteria for CCPRCC will subsequently be reclassified as of "low malignant potential" rather than carcinoma. The stroma of CCPRCC not infrequently demonstrates smooth muscle metaplasia. It should be remembered, however, that smooth muscle stromal metaplasia and proliferation are not entirely specific to this entity. Hence, it is suggested that smooth muscle metaplasia in the kidney may be a nonspecific common reaction to a variety of stimuli. Xp11 translocation renal cell carcinomas are a group of neoplasms distinguished by chromosomal translocations with breakpoints involving the TFE3 transcription factor gene, which maps to the Xp11.2 locus. The most distinctive histologic pattern of the Xp11 translocation renal cell carcinoma is that of a neoplasm with both clear cells and papillary architecture, and abundant psammoma bodies. TFE3 immunohistochemical staining is reported to be sensitive and specific for a diagnosis of translocation-associated carcinoma as long as the labeling is strong, diffuse, and nuclear. This immunostaining is particularly useful if the differential diagnosis includes CCRCC and CCPRCC. In conclusion, recognition of CCRCC and differentiation from other renal cell neoplasms with clear cytoplasm is important not only for prognostication but also for treatment-related reasons.

Treatment effects in prostate cancer following traditional and emerging therapies.

Treatment options for prostate cancer consist of radical prostatectomy, hormonal therapy and radiation therapy. Hormonal and radiation therapy have well-known, often profound, effects on the histological appearance of benign and malignant prostate tissue. Novel therapies including focal ablative treatments, chemotherapies and targeted molecular therapies are beginning to emerge and pathologists will play a central role in documenting the effects of these treatments at the tissue level. As such, knowledge of treatment-related changes and access to clinical information are essential to ensure accurate interpretation and reporting of post-treatment prostate specimens by pathologists.

VEGF and VEGFR polymorphisms affect clinical outcome in advanced renal cell carcinoma patients receiving first-line sunitinib.

BACKGROUND: Currently, sunitinib represents one of the therapeutic strongholds for renal cell carcinoma, but the criteria for treatment selection are lacking. We assessed the role of vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) polymorphisms in the prediction of the clinical outcome in metastatic renal cell carcinoma (mRCC) patients. METHODS: A total of 84 tumour samples from mRCC patients receiving first-line sunitinib were tested for VEGF and VEGFR single-nucleotide polymorphisms (SNPs). The SNP results were correlated with progression-free survival (PFS) and overall survival (OS). RESULTS: Median PFS was 8.22 months, although whereas median OS was 32.13 months. The VEGF A rs833061 resulted significant in PFS (17 vs 4 months; P<0.0001) and OS (38 vs 10 months; P<0.0001). The VEGF A rs699947 was significant for PFS (18 vs 4 months; P=0.0001) and OS (37 vs 16 months; P<0.0001). The VEGF A rs2010963 was significant in PFS (18 vs 8 vs 2 months; P=0.0001) and OS (31 vs 36 vs 9 months; P=0.0045). The VEGR3 rs6877011 was significant in PFS (12 vs 4 months; P=0.0075) and OS (36 vs 17 months; P=0.0001). At multivariate analysis, rs833061, rs2010963 and rs68877011 were significant in PFS, and rs833061 and rs68877011 were independent factors in OS. CONCLUSIONS: In our analysis, patients with TT polymorphism of rs833061, CC polymorphism of rs699947, CC polymorphism of rs2010963 and CG polymorphism of rs6877011 seem to have a worse PFS and OS when receiving first-line sunitinib.

A contemporary update on pathology reporting for urinary bladder cancer.

Providing the best management for patients with bladder cancer relies on close cooperation among uro-oncologists and pathologists. The pathologist is involved in the diagnosis and assessment of prognostic and therapeutic factors in bladder biopsies, transurethral resection (TUR) and cystectomy specimens. The pathologist must report accurately the key features using terms that are well understood by clinicians. Adequate clinical information is important to pathologists in deciding the best approach in handling and processing the surgical specimens.

Immunohistochemical expression and localization of somatostatin receptors in normal prostate, high grade prostatic intraepithelial neoplasia and prostate cancer and its many faces.

Data on the immunohistochemical expression and localization of the five somatostatin receptors (SSTRs) have been obtained by our group in separate studies concerning the many faces of prostate cancer (PCa), its precursor high grade prostatic intraepithelial neoplasia (HGPIN) and normal epithelium (Nep). This publication highlights the key findings, with special reference to: normal prostate epithelium; untreated HGPIN and PCa, both clinically and incidentally detected; PCa with NE differentiation; HGPIN and PCa following complete androgen ablation (CAA); and hormone refractory (HR) PCa. Taken together, the data obtained in these investigations demonstrate that SSTR profiling in individual patients with HGPIN and the multifaceted PCa is feasible and is of relevance to better tailor the somatostatin analogue-based treatment.

Is there a role for prostate tumour overexpressed-1 in the diagnosis of HGPIN and of prostatic adenocarcinoma? A comparison with alpha-methylacyl CoA racemase.

Prostate Tumour Overexpressed-1 (PTOV1) was recently identified as a novel gene and protein during a differential display screening for genes overexpressed in prostate cancer (PCa). Alpha-Methyl-CoA racemase (AMACR) mRNA was identified as being overexpressed in PCa. PTOV1 and racemase were immunohistochemically evaluated in PCa, high-grade prostatic intraepithelial neoplasia (HGPIN), atrophy and normal-looking epithelium (NEp) in 20 radical prostatectomies (RPs) with pT2a Gleason score 6 prostate cancer with the aim of analyzing the differences in marker expression between PTOV1 and AMACR. The level of expression of PTOV1 and AMACR increased from NEp and atrophy through HGPIN, away from and adjacent to prostate cancer, to PCa. With the ROC curve analysis the overall accuracy in distinguishing PCa vs HGPIN away from and adjacent to cancer was higher for AMACR than for PTOV1. In conclusion, AMACR can be considered a more accurate marker than PTOV1 in the identification of HGPIN and of PCa. However, PTOV1 may aid in the diagnosis of PCa, at least to supplement AMACR as another positive marker of carcinoma and to potentially increase diagnostic accuracy.

Global acetylation and methylation changes predict papillary urothelial neoplasia of low malignant potential recurrence: a quantitative analysis.

Papillary urothelial neoplasia of low malignant potential (PUNLMP) recurs in approximately 35% of patients. Conventional histopathological assessment does not distinguish non-recurrent from recurrent PUNLMP. The aim of this study is to explore the differences in global histone acetylation and global DNA methylation between non-recurrent and recurrent PUNLMP. Acetylated histone H3 lysine 9 (AcH3K9) and 5-methylcytosine (5MeC) were investigated by immunohistochemistry (IHC) in 20 PUNLMP cases (10 non-recurrent and 10 recurrent), in 5 cases of normal urothelium (NU) and in 5 cases of muscle invasive pT2 urothelial carcinoma (UC). The total optical density of the nuclear staining was measured photometrically in at least 40 nuclei separately for the basal, intermediate and luminal positions in each case. Concerning the total optical density values for both acetylation and methylation, a decrease in staining is observed from non-recurrent PUNLMP to recurrent PUNLMP, at all nuclear locations. For acetylation the mean value in non-recurrent PUNLMP, intermediate between NU and UC, is closer to the former than to latter. The mean value in recurrent PUNLMP is closer to UC than to NU. In NU, non-recurrent and recurrent PUNLMP, the acetylation to methylation ratio decreased from the nuclei in basal position to those in the surface, the average for the above groups being 1.491, 1.611 and 1.746, respectively. Setting the observed values for NU at each sampling location to unity, acetylation shows a steady decrease, the percentages of changes in this nuclear location compared to NU being -5% in non-recurrent PUNLMP, -15% in recurrent PUNLMP and -24% in UC. Concerning methylation, there is a slight increase in non-recurrent PUNLMP (+5%), a decrease in recurrent PUNLMP (-19%) followed by a sharp rise for the UC (+61%). In conclusion, there are differences in global histone acetylation and DNA methylation patterns between non-recurrent and recurrent PUNLMP. Further studies are needed to elucidate the complex interplay between chromatin structure, its modifications and recurrence of PUNLMP.