Clonal haematopoiesis: A common progenitor for cytotoxic peripheral T-cell lymphoma and angioimmunoblastic T-cell lymphoma.

Recent studies have shown that follicular helper T-cell lymphoma of angioimmunoblastic type (AITL), the most common nodal peripheral T-cell lymphoma (PTCL), frequently arises in a background of clonal haematopoiesis (CH), a preneoplastic condition affecting up to 40% of elderly individuals. Data on a potential CH association are limited for other PTCL. We report a unique patient who sequentially developed both cytotoxic PTCL, not otherwise specified and AITL with distinct T-cell receptor rearrangements but shared somatic mutations originating from the same CH clone, thus providing convincing evidence that CH can give rise to T-cell neoplasms of different lineage.

Clonal Hematopoiesis and Bone Marrow Infiltration in Patients With Follicular Helper T-Cell Lymphoma of Angioimmunoblastic Type.

Follicular helper T-cell (TFH) lymphoma harbors recurrent mutations of RHOAG17V, IDH2R172, TET2, and DNMT3A. TET2 and DNMT3A mutations are the most frequently affected genes in clonal hematopoiesis (CH). The aim of our study was to investigate the frequency of CH in bone marrow biopsies (BMB) of TFH/angioimmunoblastic T-cell lymphoma (TFH-AITL) patients and its association with myeloid neoplasms. A total of 29 BMB from 22 patients with a diagnosis of TFH-AITL were analyzed by next-generation sequencing (NGS) with a custom panel. Morphologically, 5 BMB revealed that TFH-AITL infiltrates of >5% of bone marrow (BM) cellularity confirmed in 4 cases by NGS-based T-cell clonality. IDH2R172 was demonstrated only in 1 (3%) of 29, and RHOAG17V in 2 (7%) of 29 samples. TET2 and DNMT3A were identified in 24 (83%) of 29 and 17 (59%) of 29 BMB, respectively. In the parallel lymph node the frequencies of mutations were 27% (IDH2R172), 64% (RHOAG17V), 86% (TET2), and 50% (DNMT3A). TET2 and/or DNMT3A mutations identical in lymph node and BMB were present in 18 (82%) of 22 patients, regardless of BM infiltration. In 3 cases the CH mutations were detected 13, 41, and 145 months before TFH-AITL diagnosis. Cases with TET2/DNMT3A mutations and BM variant allele frequencies >40% (7/18, 39%) showed lower blood counts. However, only low platelet count was statistically significant (P = .024). Myeloid neoplasms and/or myelodysplastic syndrome-related mutations were identified in 4 cases (4/22; 18%); all with high TET2 variant allele frequencies (>40%; P = .0114). In conclusion, CH is present in 82% of TFH-AITL and can be demonstrated up to 145 months before TFH-AITL diagnosis. NGS T-cell clonality analysis is an excellent tool to confirm TFH-AITL BM infiltration. Concurrent myeloid neoplasms were identified in 18% of the cases and were associated with TET2 mutations with high allelic burden (>40%). We demonstrated that myeloid neoplasms might occur simultaneously or precede the diagnosis of TFH lymphoma.

On the probability of lymph node negativity in pN0-staged prostate cancer-a theoretically derived rule of thumb for adjuvant needs.

PURPOSE: The extent of lymphadenectomy and clinical features influence the risk of occult nodes in node-negative prostate cancer. We derived a simple estimation model for the negative predictive value (npv) of histopathologically node-negative prostate cancer patients (pN0) to guide adjuvant treatment. METHODS: Approximations of sensitivities in detecting lymph node metastasis from current publications depending on the number of removed lymph nodes were used for a theoretical deduction of a simplified formulation of npv assuming a false node positivity of 0. RESULTS: A theoretical formula of npv = p(N0IpN0) = (100 - prevalence) / (100 - sensitivityâ€¯× prevalence) was calculated (sensitivity and preoperative prevalence in %). Depending on the number of removed lymph nodes (nLN), the sensitivity of pN0-staged prostate cancer was derived for three sensitivity levels accordingly: sensitivity = f(nLN) = 9â€¯× nLN /100 for 0 ≤ nLN ≤ 8 and f(nLN) = (nLN + 70) /100 for 9 ≤ nLN ≤ 29 and f(nLN) = 1 for nLN ≥ 30. CONCLUSION: We developed a theoretical formula for estimation of the npv in pN0-staged prostate cancer patients. It is a sine qua non to use the formula in a clinically experienced context before deciding to electively irradiate pelvic lymph nodes or to intensify adjuvant systemic treatment.

PET/MRI and genetic intrapatient heterogeneity in head and neck cancers.

PURPOSE: The relation between functional imaging and intrapatient genetic heterogeneity remains poorly understood. The aim of our study was to investigate spatial sampling and functional imaging by FDG-PET/MRI to describe intrapatient tumour heterogeneity. METHODS: Six patients with oropharyngeal cancer were included in this pilot study. Two tumour samples per patient were taken and sequenced by next-generation sequencing covering 327 genes relevant in head and neck cancer. Corresponding regions were delineated on pretherapeutic FDG-PET/MRI images to extract apparent diffusion coefficients and standardized uptake values. RESULTS: Samples were collected within the primary tumour (n = 3), within the primary tumour and the involved lymph node (n = 2) as well as within two independent primary tumours (n = 1). Genetic heterogeneity of the primary tumours was limited and most driver gene mutations were found ubiquitously. Slightly increasing heterogeneity was found between primary tumours and lymph node metastases. One private predicted driver mutation within a primary tumour and one in a lymph node were found. However, the two independent primary tumours did not show any shared mutations in spite of a clinically suspected field cancerosis. No conclusive correlation between genetic heterogeneity and heterogeneity of PET/MRI-derived parameters was observed. CONCLUSION: Our limited data suggest that single sampling might be sufficient in some patients with oropharyngeal cancer. However, few driver mutations might be missed and, if feasible, spatial sampling should be considered. In two independent primary tumours, both lesions should be sequenced. Our data with a limited number of patients do not support the concept that multiparametric PET/MRI features are useful to guide biopsies for genetic tumour characterization.

Difficulties in diagnosis of a minimal deviation adenocarcinoma of uterine cervix diagnosed postoperatively: brief communication and literature review.

PURPOSE: Rare minimal deviation adenocarcinoma (MDA) diagnosed postoperatively as incidental finding of a suspicious cervical lesion at laparoscopy, emphasizing it represents a diagnostic challenge mimicking both benign and malignant cervical lesions with often overlapping imaging characteristics-case report and literature review. CASE PRESENTATION: 35-year-old Gravida with primary infertility presented with a suspicious cervical lesion and complained about menorrhagia, hyper-/dysmenorrhea. Clinical examination was unremarkable, transvaginal scan presented a 42 × 38 × 28 mm sized cervical lesion (i.e. fibroid) without hypervascularization. Unexpectedly, the diagnosis of minimal deviation adenocarcinoma in tissue sample taken from suspicious cervical lesion at laparoscopy was revealed in final pathological report. According to suspected early stage of MDA a radical abdominal hysterectomy (PIVER III/IV), bilateral salpingo-oophorectomy, omentectomy, pelvic and para-aortic lymphadenectomy was scheduled. Final histology report confirmed: "MDA", G2, FIGO pT1b1, pN0 (0/23 LN) L0 V0 Pn0 R0. RESULTS: Ultrasonography may indicate MDA throughout the examination of vascularization/echogenicity with possibility of mimicking benign lesions with similar characteristics. Magnetic resonance imaging shows no pathognomonic signs for MDA. Subsequently, a review of literature was conducted and main factors affecting the prognosis of MDA considering diagnostic tools, clinical stage, histopathological results and surgical protocols were analyzed. CONCLUSIONS: Minimal deviation adenocarcinoma represents one of rare cervical adenocarcinomas without HPV-association. While it is crucial to differentiate benign from malignant lesions in this subtype, imaging characteristics often overlap and may not provide a specific diagnosis. Therefore, it should be considered in suspicious multicystic cervical lesions and inconclusive PAP-smear. Definitive diagnosis of this subtype should be based on cervical biopsy.

[TFH lymphoma and associated clonal hematopoiesis]. / Klonale Hämatopoese und Knochenmarkinfiltration bei Patienten mit einem nodalen Lymphom der T-follikulären Helferzellen.

T­follicular helper (TFH) cell lymphoma (TFHL) is a lymphoma of mature T cells with phenotypic characteristics and gene expression signature of TFH cells. The lymphoma harbors recurrent mutations of RHOAG17V, IDH2R172, TET2 and DNMT3A. Whereas RHOAG17V and IDH2R172 are almost exclusively found in this entity, TET2 and DNMT3A mutations occur in a broad variety of hematological neoplasms and are the most frequently affected genes in clonal hematopoiesis (CH). CH in humans shows a progression rate to overt hematologic neoplasia of about 0.5 to 1% per year, depending on clone size, number of mutations and affected genes. In 2018, the first case was described in which a lymphoid (TFHL) and myeloid (acute myeloid leukemia) neoplasm arose from a common mutated progenitor cell with shared mutations and additional private mutations. In recent years, further studies showed in up to 70% of patients with TFHL the occurrence of identical mutations of TET2 and/or DNMT3A in the myeloid cells, irrespective of bone marrow involvement, indicating a prominent role of CH in the pathogenesis of TFHL. In up to 18%, these patients show also additional synchronous or metachronous overt myeloid neoplasms, often with private myelodysplastic-type mutations, most often myelodysplastic syndrome, chronic myelomonocytic leukemia and acute myeloid leukemia. Recently, there is also evidence for two distinct lymphoid neoplasms arising from CH. TFH lymphoma cases with antecedent or concomitant hematologic neoplasm often show high variant allelic frequencies of TET2 and often more than one mutation, suggesting a role for surveillance in these patients.

Myasthenia gravis as initial presentation of a pancreatic neuroendocrine tumor: A case report.

Myasthenia gravis (MG) is a heterogeneous autoimmune disease, which is characterized by a postsynaptic neuromuscular transmission defect, with antibodies directly targeting the acetylcholine receptor (AChR) or other structural proteins of the neuromuscular junction. The majority of MG cases are associated with thymic pathologies, including thymoma, thyroiditis, autoimmune diseases or malignant hematologic neoplasia. The present study reported a rare case of AChR-positive and late-onset ocular MG, which rapidly progressed to a generalized myasthenic syndrome as an initial presentation of a pancreatic neuroendocrine neoplasia (pNEN). Following complete surgical resection of the pNEN, the myasthenic syndrome was improved and the anti-AChR antibody titers were reduced. It has been reported that MG is a paraneoplastic syndrome in thymic neoplasms and less common in hematologic malignancies. However, currently, only few cases of MG as initial presentation of a solid tumor, and more particular of a neuroendocrine neoplasm, have been reported in the literature. In conclusion, surveillance for extrathymic solid malignancies in newly diagnosed patients with MG could promote the early diagnosis of associated tumor diseases.

Targeted NGS on sequential bone marrow biopsies aids in the evaluation of cytopenias and monocytosis and documents clonal evolution-a proof of principle study.

Differential diagnosis of clonal versus reactive cytopenia and monocytosis, respectively, frequently presents a diagnostic challenge. With the two recent classifications of myeloid disorders, mutational analysis has gained importance as a diagnostic tool. However, reports on its utility on trephine bone marrow biopsies (BMB) are sparse. The aim of our proof of principle study was to determine the suitability of targeted sequencing for the longitudinal evaluation of cytopenia and monocytosis and demonstration of clonal evolution on sequential BMB. Seventy-seven EDTA-decalcified BMB of 33 patients with peripheral cytopenia and/or monocytosis, including at least one follow-up biopsy/patient, were included. Initial morphological diagnoses were idiopathic cytopenia of undetermined significance (ICUS, 8 cases), MDS (without blast increase, 7 cases), MDS with increased blasts/excess blasts (MDS-IB/EB) (11 cases), and CMML (7 cases). Thirty-one genes relevant for myeloid disorders were examined using two custom AmpliSeq NGS panels. Mutations were found in the initial BMB of 5/8 cases of ICUS, thus changing the diagnosis to clonal cytopenia of unknown significance (CCUS), 5/7 MDS, 10/11 MDS-IB/EB, and 7/7 CMML. Clonal evolution was observed in 14/33 (42%) cases, mostly associated with disease progression. None of the wild-type patients acquired mutations during follow-up. NGS-based mutation profiling is a robust diagnostic tool for BMB and provides valuable additional information, especially for cases with no/minimal dysplasia, and for better risk stratification of MDS. Tracking variant allele frequency and appearance of mutations over time allows for observing clonal evolution or relapse.

Clinical trio genome sequencing facilitates the interpretation of variants in cancer predisposition genes in paediatric tumour patients.

The prevalence of pathogenic and likely pathogenic (P/LP) variants in genes associated with cancer predisposition syndromes (CPS) is estimated to be 8-18% for paediatric cancer patients. In more than half of the carriers, the family history is unsuspicious for CPS. Therefore, broad genetic testing could identify germline predisposition in additional children with cancer resulting in important implications for themselves and their families. We thus evaluated clinical trio genome sequencing (TGS) in a cohort of 72 paediatric patients with solid cancers other than retinoblastoma or CNS-tumours. The most prevalent cancer types were sarcoma (n = 26), neuroblastoma (n = 15), and nephroblastoma (n = 10). Overall, P/LP variants in CPS genes were identified in 18.1% of patients (13/72) and P/LP variants in autosomal-dominant CPS genes in 9.7% (7/72). Genetic evaluation would have been recommended for the majority of patients with P/LP variants according to the Jongmans criteria. Four patients (5.6%, 4/72) carried P/LP variants in autosomal-dominant genes known to be associated with their tumour type. With the immediate information on variant inheritance, TGS facilitated the identification of a de novo P/LP in NF1, a gonadosomatic mosaic in WT1 and two pathogenic variants in one patient (DICER1 and PALB2). TGS allows a more detailed characterization of structural variants with base-pair resolution of breakpoints which can be relevant for the interpretation of copy number variants. Altogether, TGS allows comprehensive identification of children with a CPS and supports the individualised clinical management of index patients and high-risk relatives.

Analysis of the clinical relevance of antimitochondrial antibodies to the ß- and γ-subunits of the F1F0-ATPase in patients with primary biliary cirrhosis.

BACKGROUND: In a recent study we showed that in patients with primary biliary cirrhosis (PBC) being positive or negative for anti-M2 antibodies reacting with the 2-oxoacid-dehydrogenase complex (ODC) also antibodies to the beta- and gamma-subunits of F1F0-ATPase (anti-ß, anti-γ) occur. This is a mitochondrial enzyme but parts are also expressed on plasma membranes of endothelial cells. Here we wanted to analyse in more detail their clinical relevance. METHODS: Fifty-nine untreated and histologically defined PBC patients who had been followed for at least five years were included into the study (51 anti-M2 positive, 8 anti-M2 negative). Twenty-three of them were treated in the follow up with ursodeoxycholic acid (UDCA), eight received during a trial methotrexate (MTX). In 13 patients orthotopic liver transplantation (OLT) had to be performed. Serum samples before and during therapy were available. Patients were analysed with respect to laboratory parameters, disease activity and histological stages.Patients' sera were tested by ELISA for IgG- and IgM-antibodies against the beta- and gamma-subunits which had been recombinant expressed in E.coli and highly purified by electro-elution from SDS-gels after electrophoresis. RESULTS: Fifty-nine percent of the anti-M2 positive and 50% of the anti-M2 negative PBC patients had anti-ß- and/or anti-γ-antibodies. There were no differences between anti-ß- and/or anti-γ-antibody positive or negative patients with respect to biochemical parameters, immunoglobulins, histological stages or disease activity. Antibody reactivity significantly decreased during UDCA and MTX-treatment and also after OLT. CONCLUSIONS: Antibodies to the ß- and γ-subunits of F1F0-ATPase occur in anti-M2 positive and -negative PBC but do not have any relevance with respect to clinical activity or prognosis. However, in contrast to the anti-M2 antibodies they decrease during UDCA and immunosuppressive therapy.

A unifying hypothesis for PNMZL and PTFL: morphological variants with a common molecular profile.

Pediatric nodal marginal zone lymphoma (PNMZL) is an uncommon B-cell neoplasm affecting mainly male children and young adults. This indolent lymphoma has distinct characteristics that differ from those of conventional nodal marginal zone lymphoma (NMZL). Clinically, it exhibits overlapping features with pediatric-type follicular lymphoma (PTFL). To explore the differences between PNMZL and adult NMZL and its relationship to PTFL, a series of 45 PNMZL cases were characterized morphologically and genetically by using an integrated approach; this approach included whole-exome sequencing in a subset of cases, targeted next-generation sequencing, and copy number and DNA methylation arrays. Fourteen cases (31%) were diagnosed as PNMZL, and 31 cases (69%) showed overlapping histologic features between PNMZL and PTFL, including a minor component of residual serpiginous germinal centers reminiscent of PTFL and a dominant interfollicular B-cell component characteristic of PNMZL. All cases displayed low genomic complexity (1.2 alterations per case) with recurrent 1p36/TNFRSF14 copy number-neutral loss of heterozygosity alterations and copy number loss (11%). Similar to PTFL, the most frequently mutated genes in PNMZL were MAP2K1 (42%), TNFRSF14 (36%), and IRF8 (34%). DNA methylation analysis revealed no major differences between PTFL and PNMZL. Genetic alterations typically seen in conventional NMZL were absent in PNMZL. In summary, overlapping clinical, morphologic, and molecular findings (including low genetic complexity; recurrent alterations in MAP2K1, TNFRSF14, and IRF8; and similar methylation profiles) indicate that PNMZL and PTFL are likely part of a single disease with variation in the histologic spectrum. The term "pediatric-type follicular lymphoma with and without marginal zone differentiation" is suggested.

Synoptic Diagnostics of Myeloproliferative Neoplasms: Morphology and Molecular Genetics.

The diagnosis of a myeloid neoplasm relies on a combination of clinical, morphological, immunophenotypic and genetic features, and an integrated, multimodality approach is needed for precise classification. The basic diagnostics of myeloid neoplasms still rely on cell counts and morphology of peripheral blood and bone marrow aspirate, flow cytometry, cytogenetics and bone marrow trephine biopsy, but particularly in the setting of Ph- myeloproliferative neoplasms (MPN), the trephine biopsy has a crucial role. Nowadays, molecular studies are of great importance in confirming or refining a diagnosis and providing prognostic information. All myeloid neoplasms of chronic evolution included in this review, nowadays feature the presence or absence of specific genetic markers in their diagnostic criteria according to the current WHO classification, underlining the importance of molecular studies. Crucial differential diagnoses of Ph- MPN are the category of myeloid/lymphoid neoplasms with eosinophilia and gene rearrangement of PDGFRA, PDGFRB or FGFR1, or with PCM1-JAK2, and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). This review focuses on morphological, immunophenotypical and molecular features of BCR-ABL1-negative MPN and their differential diagnoses. Furthermore, areas of difficulties and open questions in their classification are addressed, and the persistent role of morphology in the area of molecular medicine is discussed.

Forecasting the future number of pertussis cases using data from Google Trends.

BACKGROUND: Alternative methods could be used to enhance the monitoring and forecasting of re-emerging conditions such as pertussis. Here, whether data on the volume of Internet searching on pertussis could complement traditional modeling based solely on reported case numbers was assessed. METHODS: SARIMA models were fitted to describe reported weekly pertussis case numbers over a four-year period in Germany. Pertussis-related Google Trends data (GTD) was added as an external regressor. Predictions were made by the models, both with and without GTD, and compared with values within the validation dataset over a one-year and for a two-weeks period. RESULTS: Predictions of the traditional model using solely reported case numbers resulted in an RMSE (residual mean squared error) of 192.65 and 207.8, a mean absolute percentage error (MAPE) of 58.59 and 72.1, and a mean absolute error (MAE) 169.53 and 190.53 for the one-year and for the two-weeks period, respectively. The GTD expanded model achieved better forecasting accuracy (RMSE: 144.22 and 201.78), a MAPE 43.86, and 68.54 and a MAE of 124.46 and 178.96. Corrected Akaike Information Criteria also favored the GTD expanded model (1750.98 vs. 1746.73). The difference between the predictive performances was significant when using a two-sided Diebold-Mariano test (DM value: 6.86, p < 0.001) for the one-year period. CONCLUSION: Internet-based surveillance data enhanced the predictive ability of a traditionally based model and should be considered as a method to enhance future disease modeling.

Targeting extracellular and juxtamembrane FGFR2 mutations in chemotherapy-refractory cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (iCCA) has emerged as a promising candidate for precision medicine, especially in the case of activating FGFR2 gene fusions. In addition to fusions, a considerable fraction of iCCA patients reveals FGFR2 mutations, which might lead to uncontrolled activation of the FGFR2 pathway but are mostly of unknown functional significance. A current challenge for molecular tumor boards (MTB) is to predict the functional consequences of such FGFR2 alterations to guide potential treatment decisions. We report two iCCA patients with extracellular and juxtamembrane FGFR2 mutations. After in silico investigation of the alterations and identification of activated FGFR2 downstream targets in tumor specimens by immunohistochemistry and transcriptome analysis, the MTB recommended treatment with an FGFR-inhibiting tyrosine kinase inhibitor. Both patients developed a rapidly detectable and prolonged partial response to treatment. These two cases suggest an approach to characterize further detected FGFR2 mutations in iCCA to enable patients´ selection for a successful application of the FGFR -inhibiting drugs.

Case Report: Combined CDK4/6 and MEK Inhibition in Refractory CDKN2A and NRAS Mutant Melanoma.

There are only limited treatment options for metastatic NRAS mutant melanoma patients with resistance to immune checkpoint inhibitors. Besides activation of the mitogen-activated protein (MAP) kinase pathway, they often have additional disturbances in cell cycle regulation. However, unlike BRAF mutant melanoma, no targeted therapy has yet been approved for NRAS mutant melanoma so far. Here we present a NRAS mutant melanoma patient with response to combined binimetinib and ribociclib therapy following characterization of the molecular defects of the tumor by panel sequencing. Next generation sequencing (708 cancer genes) of a soft tissue metastasis revealed a homozygous deletion of CDKN2A in addition to the previously known NRAS mutation, as well as amplification of CCNE1 and CDK6. Immunohistochemical staining of the altered cell cycle genes confirmed loss of p16, reduced expression of p21 and high expression of CDK6 and cyclin D1. As the patient had been progressive on combined immunotherapy, targeted therapy with combined MEK and CDK4/6 inhibition was initiated as recommended by the molecular tumor board. Response to treatment was monitored with PET/CT and liquid biopsy, serum LDH, and S100. In addition, a patient-derived xenograft (PDX) was used to prove the efficacy of the two drugs in combination. Furthermore, senescence-associated beta-galactosidase staining showed that more cells were senescent under the combination treatment of binimetinib and ribociclib. Our case demonstrates how an individualized, molecular-based therapeutic approach could be found based on next-generation sequencing results. Furthermore our report highlights the fruitful and efficient collaboration of dermatooncologists, human geneticists, molecular pathologists, biochemists, radiologists, and nuclear physicians. Further studies are urgently needed to expand the very limited therapeutic landscape of NRAS mutated melanoma.

Forecasting tuberculosis using diabetes-related google trends data.

Online activity-based data can be used to aid infectious disease forecasting. Our aim was to exploit the converging nature of the tuberculosis (TB) and diabetes epidemics to forecast TB case numbers. Thus, we extended TB prediction models based on traditional data with diabetes-related Google searches. We obtained data on the weekly case numbers of TB in Germany from June 8th, 2014, to May 5th, 2019. Internet search data were obtained from a Google Trends (GTD) search for 'diabetes' to the corresponding interval. A seasonal autoregressive moving average (SARIMA) model (0,1,1) (1,0,0) [52] was selected to describe the weekly TB case numbers with and without GTD as an external regressor. We cross-validated the SARIMA models to obtain the root mean squared errors (RMSE). We repeated this procedure with autoregressive feed-forward neural network (NNAR) models using 5-fold cross-validation. To simulate a data-poor surveillance setting, we also tested traditional and GTD-extended models against a hold-out dataset using a decreased 52-week-long period with missing values for training. Cross-validation resulted in an RMSE of 20.83 for the traditional model and 18.56 for the GTD-extended model. Cross-validation of the NNAR models showed a mean RMSE of 19.49 for the traditional model and 18.99 for the GTD-extended model. When we tested the models trained on a decreased dataset with missing values, the GTD-extended models achieved significantly better prediction than the traditional models (p < 0.001). The GTD-extended models outperformed the traditional models in all assessed model evaluation parameters. Using online activity-based data regarding diabetes can improve TB forecasting, but further validation is warranted.

The evolution of pulmonary pathology in fatal COVID-19 disease: an autopsy study with clinical correlation.

The pandemia of coronavirus disease 2019 (COVID-19) has caused more than 355,000 confirmed deaths worldwide. However, publications on postmortem findings are scarce. We present the pulmonary findings in four cases of fatal COVID-19 with a spectrum of lung pathology reflecting disease course and duration, invasive therapies, and laboratory features. Early disease is characterized by neutrophilic, exudative capillaritis with microthrombosis and high levels of IL-1beta and IL-6. Later stages are associated with diffuse alveolar damage and ongoing intravascular thrombosis in small to medium-sized pulmonary vessels, occasionally with areas of infarction equivalents, accompanied by laboratory features of disseminated intravascular coagulation. In late stages, organizing pneumonia with extensive intra-alveolar proliferation of fibroblasts and marked metaplasia of alveolar epithelium can be observed. Viral RNA is encountered in the lung, with virus particles in endothelial cells and pneumocytes. In many patients, multi-organ failure with severe liver damage sets in finally, possibly as consequence of an early-onset pro-inflammatory cytokine storm and/or thrombotic microangiopathy.

Dynamics of cell-free tumour DNA correlate with treatment response of head and neck cancer patients receiving radiochemotherapy.

PURPOSE: Definitive radiochemotherapy (RCTX) with curative intent is one of the standard treatment options in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Despite this intensive therapy protocol, disease recurrence remains an issue. Therefore, we tested the predictive capacity of liquid biopsies as a novel biomarker during RCTX in patients with HNSCC. MATERIAL AND METHODS: We sequenced the tumour samples of 20 patients with locally advanced HNSCC to identify driver mutations. Subsequently, we performed a longitudinal analysis of circulating tumour DNA (ctDNA) dynamics during RCTX. Deep sequencing and UMI-based error suppression for the identification of driver mutations and HPV levels in the plasma enabled treatment-response monitoring prior, during and after RCTX. RESULTS: In 85% of all patients ctDNA was detectable, showing a significant correlation with the gross tumour volume (p-value 0.032). Additionally, the tumour allele fraction in the plasma was negatively correlated with the course of treatment (p-value <0.05). If ctDNA was detectable at the first follow-up, disease recurrence was seen later on. Circulating HPV DNA (cvDNA) could be detected in three patients at high levels, showing a similar dynamic behaviour to the ctDNA throughout treatment, and disappeared after treatment. CONCLUSIONS: Monitoring RCTX treatment-response using liquid biopsy in patients with locally advanced HNSCC is feasible. CtDNA can be seen as a surrogate marker of disease burden, tightly correlating with the gross tumour volume prior to the treatment start. The observed kinetic of ctDNA and cvDNA showed a negative correlation with time and treatment dosage in most patients.