Deep learning for diagnosis and survival prediction in soft tissue sarcoma.

BACKGROUND: Clinical management of soft tissue sarcoma (STS) is particularly challenging. Here, we used digital pathology and deep learning (DL) for diagnosis and prognosis prediction of STS. PATIENTS AND METHODS: Our retrospective, multicenter study included a total of 506 histopathological slides from 291 patients with STS. The Cancer Genome Atlas cohort (240 patients) served as training and validation set. A second, multicenter cohort (51 patients) served as an additional test set. The use of the DL model (DLM) as a clinical decision support system was evaluated by nine pathologists with different levels of expertise. For prognosis prediction, 139 slides from 85 patients with leiomyosarcoma (LMS) were used. Area under the receiver operating characteristic (AUROC) and accuracy served as main outcome measures. RESULTS: The DLM achieved a mean AUROC of 0.97 (±0.01) and an accuracy of 79.9% (±6.1%) in diagnosing the five most common STS subtypes. The DLM significantly improved the accuracy of the pathologists from 46.3% (±15.5%) to 87.1% (±11.1%). Furthermore, they were significantly faster and more certain in their diagnosis. In LMS, the mean AUROC in predicting the disease-specific survival status was 0.91 (±0.1) and the accuracy was 88.9% (±9.9%). Cox regression showed the DLM's prediction to be a significant independent prognostic factor (P = 0.008, hazard ratio 5.5, 95% confidence interval 1.56-19.7) in these patients, outperforming other risk factors. CONCLUSIONS: DL can be used to accurately diagnose frequent subtypes of STS from conventional histopathological slides. It might be used for prognosis prediction in LMS, the most prevalent STS subtype in our cohort. It can also help pathologists to make faster and more accurate diagnoses. This could substantially improve the clinical management of STS patients.

In Vitro Entero-Capillary Barrier Exhibits Altered Inflammatory and Exosomal Communication Pattern after Exposure to Silica Nanoparticles.

The intestinal microvasculature (iMV) plays multiple pathogenic roles during chronic inflammatory bowel disease (IBD). The iMV acts as a second line of defense and is, among other factors, crucial for the innate immunity in the gut. It is also the therapeutic location in IBD targeting aggravated leukocyte adhesion processes involving ICAM-1 and E-selectin. Specific targeting is stressed via nanoparticulate drug vehicles. Evaluating the iMV in enterocyte barrier models in vitro could shed light on inflammation and barrier-integrity processes during IBD. Therefore, we generated a barrier model by combining the enterocyte cell line Caco-2 with the microvascular endothelial cell line ISO-HAS-1 on opposite sides of a transwell filter-membrane under culture conditions which mimicked the physiological and inflamed conditions of IBD. The IBD model achieved a significant barrier-disruption, demonstrated via transepithelial-electrical resistance (TER), permeability-coefficient (Papp) and increase of sICAM sE-selectin and IL-8. In addition, the impact of a prospective model drug-vehicle (silica nanoparticles, aSNP) on ongoing inflammation was examined. A decrease of sICAM/sE-selectin was observed after aSNP-exposure to the inflamed endothelium. These findings correlated with a decreased secretion of ICAM/E-selectin bearing exosomes/microvesicles, as evaluated via ELISA. Our findings indicate that aSNP treatment of the inflamed endothelium during IBD may hamper exosomal/microvesicular systemic communication.

[Liquid biopsy in colorectal cancer : An overview of ctDNA analysis in tumour diagnostics]. / Liquid Biopsy im kolorektalen Karzinom : Ein Überblick zur ctDNA-Analyse in der Tumordiagnostik.

In current routine diagnostics, the gold standard to determine the genomic profile of colorectal cancers (CRCs) is using biopsy or surgically resected tissues. However, such a tissue sample cannot represent the entire tumour heterogeneity, because it only shows a local and temporal snapshot. As a complement to tumour tissue genotyping, liquid biopsies enable minimally invasive detection of all potential tumour-specific mutations and their dynamic changes for molecular profiling. Furthermore, they can be repeated in certain intervals for monitoring response to treatment, occurrence of drug resistance and detection of relapse. This review focusses on analyzing circulating cell-free tumour DNA (ctDNA), which is mostly released from apoptotic or necrotic tumour cells into the bloodstream or by active secretion of circulating tumour cells (CTCs). Nevertheless, there are some challenges in analyzing ctDNA. First, ctDNA represents only a small fraction of total circulating DNA, because there is an enormous wild-type background of cell-free DNA (cfDNA) released by healthy cells. Second, ctDNA is highly fragmented and the amount of ctDNA in the blood is very low. In this review, we discuss the potential, fields of application as well as challenges and limitations of liquid biopsy approaches. In more detail, we discuss the possibility of using liquid biopsies as a future application for molecular characterization of CRCs, particularly for monitoring CRC patients during anti-EGFR therapy to detect resistance mutations (e.g. KRAS mutations) or further therapy-relevant mutations. In addition, we investigate whether blood-based molecular profiling is a reliable addition to routine diagnostic approaches of tissue-based molecular characterization.

Renal tubular epithelial cell-derived BAFF expression mediates kidney damage and correlates with activity of proliferative lupus nephritis in mouse and men.

B-cell activating factor of the tumour necrosis factor family (BAFF) is a cytokine, mainly produced by hematopoietic cells (e.g. monocytes/macrophages, dendritic cells), indispensable for B-cell maturation. The BLISS studies have demonstrated that blocking BAFF by the human monoclonal antibody belimumab is a valuable therapeutic approach in patients with clinically and serologically active systemic lupus erythematosus (SLE). However, the defined sources of BAFF, which contributes to SLE, are still unclear. Recent findings show that BAFF expression is not restricted to myeloid cells. Since lupus nephritis is the main cause of morbidity and mortality for SLE patients, the aim of this study was to investigate whether renal tubular epithelial cells (TEC) are an important source of BAFF and thus may contribute to the pathogenesis and progression of SLE. We found BAFF expression both in cultured murine and human TEC. These results could be verified with in situ data from the kidney. Moreover, BAFF expression in the kidneys of lupus-prone MRL- Faslpr mice correlated with disease activity, and BAFF expression on TEC in biopsies of patients with diffuse proliferative lupus nephritis showed a correlation with the histopathological activity index. In vitro functional assays revealed an autocrine loop of BAFF with its binding receptors on TEC, resulting in a strong induction of colony stimulating factor-1. Finally, we identified divergent effects of BAFF on TEC depending on the surrounding milieu ('inflammatory versus non-inflammatory'). Taken together, our findings indicate that renal-derived BAFF may play an important role in the pathophysiology of the systemic autoimmune disease SLE.

Therapy susceptible germline-related BRCA 1-mutation in a case of metastasized mixed adeno-neuroendocrine carcinoma (MANEC) of the small bowel.

BACKGROUND: Adenocarcinomas or combined adeno-neuroendocrine carcinomas (MANEC) of small bowel usually have a dismal prognosis with limited systemic therapy options. This is the first description of a patient showing a germline-related BRCA1 mutated MANEC of his ileum. The tumor presented a susceptibility to a combined chemotherapy and the PARP1-inhibitor olaparib. CASE PRESENTATION: A 74-year old male patient presented with a metastasized MANEC of his ileum. Due to clinical symptoms his ileum-tumor and the single brain metastasis were removed. We verified the same pathogenic (class 5) BRCA1 mutation in different tumor locations. There was no known personal history of a previous malignant tumor. Nevertheless we identified his BRCA1 mutation as germline-related. A systemic treatment was started including Gemcitabine followed by selective internal radiotherapy (SIRT) to treat liver metastases and in the further course Capecitabine but this treatment finally failed after 9 months and all liver metastases showed progression. The treatment failure was the reason to induce an individualized therapeutic approach using combined chemotherapy of carboplatin, paclitaxel and the Poly (ADP-ribose) polymerase- (PARP)-inhibitor olaparib analogous to the treatment protocol of Oza et al. All liver metastases demonstrated with significant tumor regression after 3 months and could be removed. In his most current follow up from December 2017 (25 months after his primary diagnosis) the patient is in a very good general condition without evidence for further metastases. CONCLUSION: We present first evidence of a therapy susceptible germline-related BRCA1 mutation in small bowel adeno-neuroendocrine carcinoma (MANEC). Our findings offer a personalized treatment option. The germline background was unexpected in a 74-year old man with no previously known tumor burden. We should be aware of the familiar background in tumors of older patients as well.

[Prognostic significance of immune cell infiltrates in tumor pathology]. / Prognostische Bedeutung von Immunzellinfiltraten in der Tumorpathologie.

BACKGROUND: The quantity, distribution, activation status, cytokine profile, and spatial distribution of tumor-infiltrating immune cells have prognostic value and may be predictive of response to immunotherapies. OBJECTIVES: A survey of relevant immune cell populations including their prognostic significance in the most common types of tumors. METHODS: Nonsystematic assessment and a discussion of studies that were conducted to estimate the prognostic significance of certain immune cell subsets and the methodical approaches used. RESULTS: For many tumor entities, prognostically favorable and unfavorable immune cell populations can be differentiated. However, nonspecific cell markers that may partly summarize antithetic immune cell subsets can be employed. Differences in sampling procedures and the determination of cut-off levels further limit the comparability of the studies carried out so far. CONCLUSION: The phenotypic and functional heterogeneity of tumor-infiltrating immune cells requires the use of cell subset-specific antibodies and antibody combinations. Furthermore, harmonized assessment routines, validation studies, and meta-analyses are important prerequisites for potential diagnostic implementation.

[Digital pathology in immuno-oncology-current opportunities and challenges : Overview of the analysis of immune cell infiltrates using whole slide imaging]. / Digitale Pathologie in der Immunonkologie ­ Aktuelle Chancen und Herausforderungen : Überblick zur Analyse von Immunzellinfiltraten mittels Whole Slide Imaging.

BACKGROUND: Immuno-oncology requires objective and standardized methods for measuring immune cell infiltrates for therapy selection and clinical trials. METHODS: Current approaches in applying digital pathology in immuno-oncology and developments in computational image analysis were analyzed. RESULTS: Since 2008, digital pathology has had an ever increasing importance in immuno-oncology. It is currently the only technology allowing the systematic and cost-effective quantitative spatial immune-profiling of patients. The analysis of immunological biomarkers requires integrated staining and image analysis strategies from single- to multistain on slide stacks. Statistical limits of the hypothesis to be tested have to be taken into account. Digital image analysis opens a new technological role for pathology in immuno-oncology and thereby serves as a key technological driver. CONCLUSION: Digital pathology delivers objective and quantitative data on the tumor microenvironment. But currently, a fully automatic, high-throughput analytics capability is still missing. Deep learning is the remedy for this, as it improves image analysis with increasing data availability. This requires the creation of systematic data collections but will in the end deliver standardized and automatic immunological analyses.

Implementation of an HIV-1 Triple-Target NAT Assay in the Routine Screening at Three German Red Cross Blood Centres.

BACKGROUND: Blood product safety was significantly improved by the introduction of NAT testing in the late 1990s, resulting in a strong decrease of transfusion-transmitted infections (TTIs). Due to the occurrence of HIV-1 NAT test failures as a consequence of mismatch mutations in the amplicon regions of mono-target NAT assays, the Paul Ehrlich Institute mandated the implementation of multi-target NAT assays for HIV-1 in 2014. Commercial suppliers mostly developed dual-target NAT assays, with only one implementing a triple-target NAT assay. METHODS: The HIV-1 triple-target NAT assay v3 (GFE Blut) was tested on mutated specimens and synthetic DNA bearing mutations that resulted in sample underquantification or false-negative test results. In addition, data from 2 years routine testing at three German Red Cross Blood centres were analysed. RESULTS: The HIV-1 triple-target PCR could compensate for all mutations tested and could compensate the loss of one amplicon without a significant loss of sensitivity. Data from 2 years routine testing showed a solid performance. CONCLUSION: The HIV-1 triple-target v3 assay (GFE Blut) can compensate mutations in target sequences better than a dual-target assay and is applicable to high-throughput screening, thus increasing blood product safety.

[Grading of prostate cancer]. / Grading von Prostatakarzinomen.

The current grading of prostate cancer is based on the classification system of the International Society of Urological Pathology (ISUP) following a consensus conference in Chicago in 2014. The foundations are based on the frequently modified grading system of Gleason. This article presents a brief description of the development to the current ISUP grading system.

Next-generation sequencing reveals novel differentially regulated mRNAs, lncRNAs, miRNAs, sdRNAs and a piRNA in pancreatic cancer.

BACKGROUND: Previous studies identified microRNAs (miRNAs) and messenger RNAs with significantly different expression between normal pancreas and pancreatic cancer (PDAC) tissues. Due to technological limitations of microarrays and real-time PCR systems these studies focused on a fixed set of targets. Expression of other RNA classes such as long intergenic non-coding RNAs or sno-derived RNAs has rarely been examined in pancreatic cancer. Here, we analysed the coding and non-coding transcriptome of six PDAC and five control tissues using next-generation sequencing. RESULTS: Besides the confirmation of several deregulated mRNAs and miRNAs, miRNAs without previous implication in PDAC were detected: miR-802, miR-2114 or miR-561. SnoRNA-derived RNAs (e.g. sno-HBII-296B) and piR-017061, a piwi-interacting RNA, were found to be differentially expressed between PDAC and control tissues. In silico target analysis of miR-802 revealed potential binding sites in the 3' UTR of TCF4, encoding a transcription factor that controls Wnt signalling genes. Overexpression of miR-802 in MiaPaCa pancreatic cancer cells reduced TCF4 protein levels. Using Massive Analysis of cDNA Ends (MACE) we identified differential expression of 43 lincRNAs, long intergenic non-coding RNAs, e.g. LINC00261 and LINC00152 as well as several natural antisense transcripts like HNF1A-AS1 and AFAP1-AS1. Differential expression was confirmed by qPCR on the mRNA/miRNA/lincRNA level and by immunohistochemistry on the protein level. CONCLUSIONS: Here, we report a novel lncRNA, sncRNA and mRNA signature of PDAC. In silico prediction of ncRNA targets allowed for assigning potential functions to differentially regulated RNAs.

[Cell death in malignant tumors. Relevance of cell death regulation for metastasis]. / Zelluntergänge in malignen Tumoren. Relevanz der Zelltodregulation für Metastasierung.

Defects in the regulation of cell death are important causes for both the development and therapy resistance of malignant tumors. Several distinct, molecularly defined types of cell death are known, such as apoptosis, anoikis, and necroptosis. Moreover, the specific triggering of cell death plays an important role in the prevention of metastasis. The results of recent studies have shown that various types of cell death are pivotal at different steps of the metastasis cascade, in order to prevent cellular detachment, migration, invasion, intravasation, extravasation and the establishment of micrometastasis and macrometastasis. At the subcellular level, numerous links exist between cell death regulation and metastasis, specifically regarding signaling pathways and individual proteins with dual or multiple functions. As an example, the decoy receptor 3 protein (DcR3) functions both as an anti-apoptotic protein and as a direct promotor of invasion and migration of tumor cells. In summary, the specific triggering of cell death plays a pivotal role for the prevention of metastasis. On the other hand, the stepwise process of metastasis represents a mechanism of selection resulting in established metastases with a multiresistant phenotype which corresponds to the clinical observation that many metastasized cancers are therapy resistant. In the future, innovative diagnostic tests to individually predict the resistance pattern and possibilities to overcome resistance are urgently needed.

How safe is safe: new human immunodeficiency virus Type 1 variants missed by nucleic acid testing.

BACKGROUND: Nucleic acid amplification techniques (NAT) in routine blood donor screening considerably reduce the diagnostic window phase period. Nevertheless, several reports of false-negative NAT results were published. Here, four cases of human immunodeficiency virus Type 1 (HIV-1) RNA-positive blood donations that escaped detection by NAT screening are described. STUDY DESIGN AND METHODS: A total of 2.7 million blood donations were screened for viral infections between January 2010 and October 2012 in our German Red Cross blood donation service. Four plasma specimens with false-negative NAT results were comparatively investigated with 12 CE-marked NAT assays. In two cases of putative HIV-1 variants the target region of the NAT assay was sequenced allowing comparison with the respective primers and probes. RESULTS: Most of the NAT assays used in routine blood donor screening with the 5'-long terminal repeat (LTR) as target region demonstrated deficiencies in detecting the viral variants and the low-viral-carrier donations. Sequence analysis revealed in one case a deletion of 56 nucleotides within the 5'-LTR preventing the binding of the probe accompanied by a neighbored insertion of another 52 nucleotides and several primer mismatches in another case. No false-negative results were obtained for these cases using dual-target assays. The viral load of the remaining two false-negative results was below the NAT's limit of detection. CONCLUSION: HIV-1 is characterized by a high mutation rate and rapid generation of new viral variants. By the use of one target region for HIV-1 NAT assays there is a certain risk of false-negative results. Employing HIV-1 multi- and dual-target assays in routine blood donor screening seems to be a reasonable possibility to minimize this problem.

Preoperative therapy of esophagogastric cancer: the problem of nonresponding patients.

INTRODUCTION: Preoperative treatment is nowadays standard for locally advanced esophagogastric cancer in Europe. Surprisingly, little attention has been paid to nonresponders so far. The aim of our retrospective exploratory study was the comparison of responder, nonresponder, and primary resected patients in respect of outcome considering the tumor entity. PATIENTS AND METHODS: From 2001-2011, 607 patients with locally advanced esophagogastric carcinoma (adenocarcinoma of the esophagogastric junction (AEG), n = 293; squamous cell cancer (SCC), n = 111; gastric cancer, n = 203) after preoperative treatment (n = 281) or primary resection (n = 326) were included. Histopathological response evaluation (Becker criteria) was available for 263. RESULTS: A total of 76/263 (28.9 %) were responders (<10 % residual tumor). There was an association of response with increased R0 resections (p < 0.001) but also with a higher complication rate (p = 0.008) compared to nonresponse and primary surgery. Mortality was not influenced. Increased R0 resections after response were confirmed in every tumor entity (AEG, p = 0.010; SCC, p = 0.023; gastric cancer, p = 0.006). Median survival was best for responders with 43.5 months [95 % confidence interval (CI), 27.9-59.1], followed by nonresponders with 24.3 months (95 % CI, 21.6-27.0) and primary resected patients with 20.8 months (95 % CI, 17.7-23.9; p = 0.002). AEG (p = 0.012) and gastric cancer (p = 0.017) revealed identical results, but in the subgroup of SCC, the survival of nonresponders (median, 11.6 months; 95 % CI, 6.9-16.3) was even worse than for primary resected patients (median, 23.8 months; 95 % CI, 1.7-46.0; p = 0.012). CONCLUSION: The histopathological response rate was low. Generally, nonresponding patients with AEG or gastric cancer seem not to have a disadvantage compared to primary resected patients, but nonresponders with SCC have a worse prognosis, which strengthens the demand for a critical patient selection in surgery for this tumor entity.

Development of miliary tuberculosis under infliximab in a patient with spondyloarthritis and suspected Crohn's disease.

Tuberculosis (TB) infection is a major concern in patients with chronic autoimmune conditions under immunosuppressive therapy. Gastrointestinal tuberculosis can be misdiagnosed as Crohn's disease with detrimental consequences for the patient. We report on a 40-year old ethnic Turkish patient with HLA-B27 positive spondyloarthritis who developed gastrointestinal symptoms under immunosuppressive treatment with infliximab. Crohn's disease was diagnosed at a primary care hospital and immunosuppressive treatment was escalated. Initial diagnostic tests for tuberculosis were negative. When the clinical condition deteriorated, the patient was transferred to our intensive care unit for further diagnosis and treatment. Tuberculosis was suspected due to clinical presentation and radiological signs and anti-tuberculous treatment was initiated. After the onset of treatment, first microbiological results confirmed the diagnosis of miliary TB with Mycobacterium bovis. As an infection route we assume primary gastrointestinal infection with M. bovis during the patient's annual holidays in Turkey with a rapid development of miliary TB under infliximab and escalated immunosuppressive therapy. This case report demonstrates the difficulties in differentiating intestinal TB from other granulomatous conditions such as Crohn's disease. The diagnostic tools for gastrointestinal tuberculosis are discussed in detail regarding their sensitivity, specificity as well as positive and negative predictive values.

[Biomechanics of cartilage tissue engineering constructs : Sensitive test procedure for assessment of biomechanical functionality and further development after in vivo transplantation]. / Biomechanik von Knorpel-Tissue-Engineering-Konstrukten : Sensitives Testverfahren zur Beurteilung deren biomechanischer Funktionalität und ihrer Weiterentwicklung nach In-vivo-Transplantation.

Specific biomechanical properties represent important quality markers of cartilage tissue engineering (TE) constructs. The aim of the study was to identify a sensitive biomechanical test to assess mechanical properties of cartilage TE constructs. Biomechanical testing of in vitro cultivated constructs following the very low rubber hardness (VLRH) principle illustrated significant differences between constructs cultured under chondrogenic conditions over various periods of time. An increase in proteoglycan and collagen type II deposition corresponded to increasing VLRH hardness values. Although a decrease in proteoglycan was detected after ectopic implantation of constructs into SCID mice, no reduction in biomechanical hardness values was observed. A functional estimation of TE constructs requires determination of biomechanical and biochemical parameters as quality features.

Mismatch repair deficiency, chemotherapy and survival for resectable gastric cancer: an observational study from the German staR cohort and a meta-analysis.

PURPOSE: In a post hoc analysis of the MAGIC trial, patients with curatively resected gastric cancer (GC) and mismatch repair (MMR) deficiency (MMRd) had better median overall survival (OS) when treated with surgery alone but worse median OS when treated with additional chemotherapy. Further data are required to corroborate these findings. METHODS: Between April 2013 and December 2018, 458 patients with curatively resected GC, including cancers of the esophagogastric junction Siewert type II and III, were identified in the German centers of the staR consortium. Tumor sections were assessed for expression of MLH1, MSH2, MSH6 and PMS2 by immunohistochemistry. The association between MMR status and survival was assessed. Similar studies published up to January 2021 were then identified in a MEDLINE search for a meta-analysis. RESULTS: MMR-status and survival data were available for 223 patients (median age 66 years, 62.8% male), 23 patients were MMRd (10.3%). After matching for baseline clinical characteristics, median OS was not reached in any subgroup. Compared to perioperative chemotherapy, patients receiving surgery alone with MMRd and MMRp had a HR of 0.67 (95% CI 0.13-3.37, P = 0.63) and 1.44 (95% CI 0.66-3.13, P = 0.36), respectively. The meta-analysis included pooled data from 385 patients. Compared to perioperative chemotherapy, patients receiving surgery alone with MMRd had an improved OS with a HR of 0.36 (95% CI 0.14-0.91, P = 0.03), whereas those with MMRp had a HR of 1.18 (95% CI 0.89-1.58, P = 0.26). CONCLUSION: Our data support a positive prognostic effect for MMRd in GC patients treated with surgery only and a differentially negative prognostic effect in patients treated with perioperative chemotherapy. MMR status determined by preoperative biopsies may be used as a predictive biomarker to select patients for perioperative chemotherapy in curatively resectable GC.

Expression of oestrogen receptor ß and prognosis of colorectal cancer.

BACKGROUND: Previous studies suggest that sex steroids influence colorectal cancer (CRC) carcinogenesis. The oestrogen receptor ß (ERß) is the predominantly expressed ER in the colon and loss of ERß in CRC has been associated with advanced cancer stages. METHODS: Information on vital status by the end of 2009 was obtained for 1262 CRC patients recruited between 2003 and 2007. The ERß expression was immunohistochemically measured and associations of ERß scores with overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) were evaluated using Cox proportional hazard models adjusted for prognostic factors, such as tumour stage and second primary tumours. RESULTS: Of the 1101 tumour samples with successful measurement, 535 were ERß negative (48.6%), 381 (34.6%) showed moderate and 185 (16.8%) showed high ERß expression. Compared with high ERß expression, lack of ERß was associated with higher cancer stages as well as greater tumour extent. In multivariate analyses, ERß negativity was associated with an increased hazard ratio for death (HR=1.61, 95% CI 1.09-2.40, P=0.02), death attributed to CRC (HR=1.54, 95% CI 0.99-2.39, P=0.06) as well as a poorer DFS (DFS HR=1.64, 95% CI 1.23-3.36, P=0.04). The associations were stronger in stage I-III patients (OS HR=2.20, 95% CI 1.28-4.06, P=0.007, DSS HR=2.38, 95% CI 1.20-5.39, P=0.02, respectively). CONCLUSIONS: Lack of ERß expression is associated with advanced cancer stages and independently associated with poor survival.

Verrucous carcinoma in epidermolysis bullosa simplex is possibly associated with a novel mutation in the keratin 5 gene.

Epidermolysis bullosa simplex (EBS) is mainly caused by mutations in the KRT5 and KRT14 genes. Squamous cell carcinoma (SCC) represents the second most frequent skin neoplasia with complex aetiology. The molecular events disrupting the orchestrated interplay between the cytoskeleton, cell adhesion molecules and signalling proteins are ill understood in SCC. We describe the molecular background and the unusual course of the disease in a patient with EBS Dowling-Meara, severe keratoderma and a massive verrucous carcinoma. Skin and tumour samples from the patient were analysed using light microscopy, immunohistochemistry and immunofluorescence mapping. Mutation analysis of the KRT5 and KRT14 genes identified the novel KRT5 mutation p.E477D. Invasive tumour areas were characterized by downregulation of keratins 5 and 14, reduced and irregular desmocollin-2 expression and increased expression of keratins 6, 16 and 17. Levels of Ki-67 were increased and levels of E-cadherin strongly reduced in the tumour tissue. In this case a novel KRT5 mutation led to increased fragility of keratinocytes. Desmosome and adherens junctions were destabilized, which may trigger keratinocyte-mediated inflammation, possibly via p120-catenin-dependent signalling, suggesting a link between a keratin mutation and SCC, which adds weight to the hypothesis that disturbance of the cytoskeleton represents a major cause in the appearance of the malignant phenotype. Some individuals with EBS may be at risk of developing secondary SCC.