Antibody-suppressor CXCR5+ CD8+ T cellular therapy ameliorates antibody-mediated rejection following kidney transplant in CCR5 KO mice.

CCR5 KO kidney transplant (KTx) recipients are extraordinarily high alloantibody producers and develop pathology that mimics human antibody-mediated rejection (AMR). C57BL/6 and CCR5 KO mice (H-2b ) were transplanted with A/J kidneys (H-2a ); select cohorts received adoptive cell therapy (ACT) with alloprimed CXCR5+ CD8+ T cells (or control cells) on day 5 after KTx. ACT efficacy was evaluated by measuring posttransplant alloantibody, pathology, and allograft survival. Recipients were assessed for the quantity of CXCR5+ CD8+ T cells and CD8-mediated cytotoxicity to alloprimed IgG+ B cells. Alloantibody titer in CCR5 KO recipients was four-fold higher than in C57BL/6 recipients. The proportion of alloprimed CXCR5+ CD8+ T cells 7 days after KTx in peripheral blood, lymph node, and spleen was substantially lower in CCR5 KO compared to C57BL/6 recipients. In vivo cytotoxicity towards alloprimed IgG+ B cells was also reduced six-fold in CCR5 KO recipients. ACT with alloprimed CXCR5+ CD8+ T cells (but not alloprimed CXCR5- CD8+ or third-party primed CXCR5+ CD8+ T cells) substantially reduced alloantibody titer, ameliorated AMR pathology, and prolonged allograft survival. These results indicate that a deficiency in quantity and function of alloprimed CXCR5+ CD8+ T cells contributes to high alloantibody and AMR in CCR5 KO recipient mice, which can be rescued with ACT.

Proliferative Glomerulonephritis With Monoclonal IgG1κ Deposits in a Hepatitis C Virus-Positive Patient.

Hepatitis C virus infection is associated with several glomerular diseases, most commonly cryoglobulinemic glomerulonephritis, which is typically secondary to type II mixed cryoglobulinemia. We present a patient with hepatitis C virus infection and cryoglobulinemic glomerulonephritis secondary to type I (monoclonal) cryoglobulinemia that is likely related to a concurrent hepatitis C virus infection-associated lymphoproliferative disorder. We list the differential diagnosis of cryoglobulinemic glomerulonephritis. Additionally, the case draws attention to the possibility that, rarely, even clinically undetectable "occult" B-cell lymphoproliferative disorders may result in significant kidney disease.

Gray zone lymphoma with features intermediate between classical Hodgkin lymphoma and diffuse large B-cell lymphoma: characteristics, outcomes, and prognostication among a large multicenter cohort.

Gray zone lymphoma (GZL) with features between classical Hodgkin lymphoma and diffuse large B-cell lymphoma (DLBCL) is a recently recognized entity reported to present primarily with mediastinal disease (MGZL). We examined detailed clinical features, outcomes, and prognostic factors among 112 GZL patients recently treated across 19 North American centers. Forty-three percent of patients presented with MGZL, whereas 57% had non-MGZL (NMGZL). NMGZL patients were older (50 versus 37 years, P = 0.0001); more often had bone marrow involvement (19% versus 0%, P = 0.001); >1 extranodal site (27% versus 8%, P = 0.014); and advanced stage disease (81% versus 13%, P = 0.0001); but they had less bulk (8% versus 44%, P = 0.0001), compared with MGZL patients. Common frontline treatments were cyclophosphamide-doxorubicin-vincristine-prednisone +/- rituximab (CHOP+/-R) 46%, doxorubicin-bleomycin-vinblastine-dacarbazine +/- rituximab (ABVD+/-R) 30%, and dose-adjusted etoposide-doxorubicin-cyclophosphamide-vincristine-prednisone-rituximab (DA-EPOCH-R) 10%. Overall and complete response rates for all patients were 71% and 59%, respectively; 33% had primary refractory disease. At 31-month median follow-up, 2-year progression-free survival (PFS) and overall survival rates were 40% and 88%, respectively. Interestingly, outcomes in MGZL patients seemed similar compared with that of NMGZL patients. On multivariable analyses, performance status and stage were highly prognostic for survival for all patients. Additionally, patients treated with ABVD+/-R had markedly inferior 2-year PFS (22% versus 52%, P = 0.03) compared with DLBCL-directed therapy (CHOP+/-R and DA-EPOCH-R), which persisted on Cox regression (hazard ratio, 1.88; 95% confidence interval, 1.03-3.83; P = 0.04). Furthermore, rituximab was associated with improved PFS on multivariable analyses (hazard ratio, 0.35; 95% confidence interval, 0.18-0.69; P = 0.002). Collectively, GZL is a heterogeneous and likely more common entity and often with nonmediastinal presentation, whereas outcomes seem superior when treated with a rituximab-based, DLBCL-specific regimen.

Classification of follicular lymphoma: the effect of computer aid on pathologists grading.

BACKGROUND: Follicular lymphoma (FL) is one of the most common lymphoid malignancies in the western world. FL cases are stratified into three histological grades based on the average centroblast count per high power field (HPF). The centroblast count is performed manually by the pathologist using an optical microscope and hematoxylin and eosin (H&E) stained tissue section. Although this is the current clinical practice, it suffers from high inter- and intra-observer variability and is vulnerable to sampling bias. METHODS: In this paper, we present a system, called Follicular Lymphoma Grading System (FLAGS), to assist the pathologist in grading FL cases. We also assess the effect of FLAGS on accuracy of expert and inexperienced readers. FLAGS automatically identifies possible HPFs for examination by analyzing H&E and CD20 stains, before classifying them into low or high risk categories. The pathologist is first asked to review the slides according to the current routine clinical practice, before being presented with FLAGS classification via color-coded map. The accuracy of the readers with and without FLAGS assistance is measured. RESULTS: FLAGS was used by four experts (board-certified hematopathologists) and seven pathology residents on 20 FL slides. Access to FLAGS improved overall reader accuracy with the biggest improvement seen among residents. An average AUC value of 0.75 was observed which generally indicates "acceptable" diagnostic performance. CONCLUSIONS: The results of this study show that FLAGS can be useful in increasing the pathologists' accuracy in grading the tissue. To the best of our knowledge, this study measure, for the first time, the effect of computerized image analysis on pathologists' grading of follicular lymphoma. When fully developed, such systems have the potential to reduce sampling bias by examining an increased proportion of HPFs within follicle regions, as well as to reduce inter- and intra-reader variability.

Complete response to induction therapy in patients with Myc-positive and double-hit non-Hodgkin lymphoma is associated with prolonged progression-free survival.

BACKGROUND: Myc-positive B-cell non-Hodgkin lymphoma (NHL) with or without a B-cell chronic lymphocytic leukemia/lymphoma 2 (BCL2) rearrangement is associated with inferior progression-free survival (PFS) and overall survival (OS). In this study, the authors reviewed the outcomes of patients with myc-positive and double-hit NHL at The Ohio State University. METHODS: All patients who had non-Burkitt, aggressive B-cell NHL from 2008 to 2011 were assessed for the t(14;18) translocation and for v-myc avian myelocytomatosis viral oncogene homolog (CMYC) rearrangements at diagnosis, and all myc-positive patients were included in the current analysis. Associations with clinical characteristics were described, and univariable and multivariable models were used to assess correlations between clinical variables and outcomes. RESULTS: Of 49 myc-positive patients, 29 patients also had BCL2 rearrangements (double-hit NHL). No patients underwent autologous stem cell transplantation in first remission. For all myc-positive patients, the median PFS was 16.6 months, and the median OS was 37.7 months. For patients who had double-hit NHL, the median PFS was 8 months, and the median OS was 12.5 months; whereas the median PFS and OS were not reached for myc-positive patients. A complete response (CR) after front-line therapy, the presence of t(14;18), International Prognostic Index (IPI) group, and age were associated with PFS; whereas only the achievement of a CR and age >60 years were associated with OS in the multivariable setting. The median PFS was 3.3 months, and the median and OS was 7.0 months for patients who did not attain a CR; and the medians were not reached for patients who achieved a CR (P < .00001). CONCLUSIONS: The achievement of a CR with front-line therapy is associated with a prolonged PFS and OS in patients with myc-positive NHL, even after adjusting for type of initial therapy, histology, age, IPI, or the presence of a concurrent BCL2 translocation.

Expression of cancer-testis antigens MAGEA1, MAGEA3, ACRBP, PRAME, SSX2, and CTAG2 in myxoid and round cell liposarcoma.

Myxoid and round-cell liposarcoma is a frequently encountered liposarcoma subtype. The mainstay of treatment remains surgical excision with or without chemoradiation. However, treatment options are limited in the setting of metastatic disease. Cancer-testis antigens are immunogenic antigens with the expression largely restricted to testicular germ cells and various malignancies, making them attractive targets for cancer immunotherapy. Gene expression studies have reported the expression of various cancer-testis antigens in liposarcoma, with mRNA expression of CTAG1B, CTAG2, MAGEA9, and PRAME described specifically in myxoid and round-cell liposarcoma. Herein, we further explore the expression of the cancer-testis antigens MAGEA1, ACRBP, PRAME, and SSX2 in myxoid and round-cell liposarcoma by immunohistochemistry in addition to determining mRNA levels of CTAG2 (LAGE-1), PRAME, and MAGEA3 by quantitative real-time PCR. Samples in formalin-fixed paraffin-embedded blocks (n=37) and frozen tissue (n=8) were obtained for immunohistochemistry and quantitative real-time PCR, respectively. Full sections were stained with antibodies to MAGEA1, ACRBP, PRAME, and SSX2 and staining was assessed for intensity (1-2+) and percent tumor positivity. The gene expression levels of CTAG2, PRAME, and MAGEA3 were measured by quantitative real-time PCR. In total, 37/37 (100%) of the samples showed predominantly strong, homogenous immunoreactivity for PRAME. There was a variable, focal expression of MAGEA1 (11%) and SSX2 (16%) and no expression of ACRBP. Quantitative real-time PCR demonstrated PRAME and CTAG2 transcripts in all eight samples: six tumors with high mRNA levels; two tumors with low mRNA levels. The gene expression of MAGEA3 was not detected in the majority of cases. In conclusion, myxoid and round-cell liposarcomas consistently express PRAME by immunohistochemistry as well as CTAG2 and PRAME by qualitative real-time PCR. This supports the use of cancer-testis antigen-targeted immunotherapy in the treatment of this malignancy.

NY-ESO-1 is a sensitive and specific immunohistochemical marker for myxoid and round cell liposarcomas among related mesenchymal myxoid neoplasms.

Myxoid and round cell liposarcomas constitute approximately one-third of all liposarcomas, a relatively common group of fat-derived soft tissue sarcomas. The histomorphology is a continuum between highly differentiated myxoid and poorly differentiated round cell components. The gold standard of diagnosis is dependent on histomorphology and/or identification of t(12;16)(q13;p11) translocation by cytogenetics or demonstration of DDIT3 rearrangements by fluorescence in situ hybridization. There are currently no diagnostic immunohistochemical stains available. The broad range of myxoid neoplasms in the differential diagnosis includes a variety of sarcomas. Given the notable differences in disease biology among myxoid neoplasms, which range from benign to aggressive, an accurate diagnosis is imperative for proper treatment and prognostication. Prompted by our recent study showing frequent expression of the cancer testis antigen NY-ESO-1 in myxoid and round cell liposarcomas, we sought to evaluate the utility of NY-ESO-1 as an immunohistochemical marker for myxoid and round cell liposarcoma among mesenchymal myxoid neoplasms within the differential diagnosis. Formalin-fixed, paraffin-embedded blocks were obtained for the following mesenchymal myxoid neoplasms (n=138): myxoid and round cell liposarcoma (n=38); well-differentiated liposarcoma (n=12); lipoma (n=20; 4 with myxoid change); extra-cardiac soft tissue myxoma (n=39); extraskeletal myxoid chondrosarcoma (n=12); myxofibrosarcoma (n=10: 5 low grade, 2 intermediate grade, 3 high grade); and low-grade fibromyxoid sarcoma (n=7). Utilizing standard immunohistochemistry protocols, full sections were stained with NY-ESO-1 (clone E978), and staining was assessed for intensity (1-2+), percentage of tumor positivity, and location. In all, 36/38 (95%) of the myxoid and round cell liposarcomas demonstrated NY-ESO-1 immunoreactivity. The majority of the positive cases (34/36; 94%) showed strong, homogenous staining (>50% tumor positivity), and two cases (6%) showed weak (1+ intensity), patchy staining (20-30% tumor positivity). Immunoreactivity was predominantly cytoplasmic. All the other neoplasms evaluated were negative for NY-ESO-1. NY-ESO-1 appears to be a sensitive and a specific marker for myxoid and round cell liposarcoma among mesenchymal myxoid neoplasms. The assessment of NY-ESO-1 expression by immunohistochemistry in the appropriate setting provides a cheaper, faster, and more accessible confirmatory test.

The cancer-testis antigen NY-ESO-1 is highly expressed in myxoid and round cell subset of liposarcomas.

Liposarcomas are a heterogenous group of fat-derived sarcomas, and surgery with or without chemoradiation therapy remains the main stay of treatment. NY-ESO-1 is a cancer-testis antigen expressed in various cancers where it can induce both cellular and humoral immunity. Immunotherapy has shown promise in clinical trials involving NY-ESO-1-expressing tumors. Gene expression studies have shown upregulation of the gene for NY-ESO-1, CTAG1B, in myxoid and round cell liposarcomas. Herein, we evaluated the expression of NY-ESO-1 among liposarcoma subtypes by quantitative real-time PCR, western blot analysis, and immunohistochemistry. Frozen tissue for quantitative real-time PCR and western blot analysis was obtained for the following liposarcoma subtypes (n=15): myxoid and round cell (n=8); well-differentiated (n=4), and dedifferentiated (n=3). Formalin-fixed paraffin-embedded blocks were obtained for the following liposarcoma subtypes (n=44): myxoid and round cell (n=18); well-differentiated (n=10); dedifferentiated (n=10); and pleomorphic (n=6). Full sections were stained with monoclonal antibody NY-ESO-1, and staining was assessed for intensity (1-3+), percentage of tumor positivity, and location. In all, 7/8 (88%) and 16/18 (89%) myxoid and round cell expressed CTAG1B and NY-ESO-1 by quantitative real-time PCR and immunohistochemistry, respectively. Western blot correlated with mRNA expression levels. By immunohistochemistry, 94% (15/16) of positive cases stained homogenously with 2-3+ intensity. Also, 3/6 (50%) pleomorphic liposarcomas demonstrated a range of staining: 1+ intensity in 50% of cells; 2+ intensity in 5% of cells; and 3+ intensity in 90% of cells. One case of dedifferentiated liposarcoma showed strong, diffuse staining (3+ intensity in 75% of cells). Our study shows that both CTAG1B mRNA and protein are overexpressed with high frequency in myxoid and round cell liposarcoma, enabling the potential use of targeted immunotherapy in the treatment of this malignancy.

Discovered on gastrointestinal stromal tumours 1 (DOG1) expression in non-gastrointestinal stromal tumour (GIST) neoplasms.

AIMS: To further characterize discovered on GIST1 (DOG1) antibody clone K9 expression in a broad range of mesenchymal and epithelial tumours. METHODS AND RESULTS: Formalin-fixed paraffin-embedded sections of various tumours were stained with the anti-DOG1 monoclonal antibody clone K9. The tumours (n = 187) included: gastrointestinal stromal tumours (GISTs) (n = 20); malignant melanoma (n = 19); schwannoma (n = 10); neurofibroma (n = 10); leiomyosarcoma (n = 10); low-grade fibromyxoid sarcoma (n = 5); angiosarcoma, (n = 10); epithelioid sarcoma (n = 5); clear cell sarcoma (n = 3); synovial sarcoma (n = 10); malignant peripheral nerve sheath tumour (MPNST) (n = 12); alveolar soft part sarcoma (n = 3); chordoma (n = 5); pleomorphic undifferentiated sarcoma (n = 5); perineurioma (n = 4); granular cell tumour (n = 6); acinic cell carcinoma (n = 5); adenocarcinoma, lung (n = 5), colon (n = 10), endometrioid (n = 10), prostate (n = 10) and renal cell (n = 10). Nineteen of 20 GISTs expressed DOG-1 and 12 of 20 were diffusely positive (≥95%) with moderate to strong intensity. There was focal, predominantly luminal staining of colorectal (three of 10), endometrioid (four of 10) and acinic cell carcinomas (four of five). One case each of spindle cell/desmoplastic melanoma (2+), schwannoma (trace) and MPNST (2+) showed DOG-1 expression. CONCLUSIONS: Our study supports that DOG-1 is a highly sensitive and specific marker for GISTs and also highlights hitherto unrecognized and unusual patterns of expression in non-mesenchymal neoplasms.

Hypertension and the Kidney: Reduced Kidney Mass Is Bad for Both Normotensive and Hypertensive Rats.

BACKGROUND: Hypertension is a leading cause of chronic kidney disease worldwide. Early studies demonstrated the short-term effects of hypertension on kidney function and morphology in ablative nephropathy. The aim of this study was to investigate the long-term consequences of hypertension in 5/6 nephrectomy (5/6NE) model. METHODS: Reduction of the kidney mass by 5/6NE was created in spontaneous hypertensive rats (SHR) and genetically similar normotensive Wistar Kyoto (WKY) rats. Blood pressure, serum creatinine (SCr), hematuria, and proteinuria were monitored weekly for 23 weeks. Kidney morphology was assessed at the end of the study. Sham-operated rats from both strains were used as controls. RESULTS: Rats with 5/6NE had increased SCr, blood pressure, hematuria, and proteinuria in both SHR and WKY. Even though the SCr levels and blood pressure were greater in 5/6NE SHR as compared with 5/6NE WKY rats, absolute changes from sham-operated rats were not statistically significant between these 2 groups. 5/6NE SHR had earlier onset and higher proteinuria than 5/6NE WKY rats. Hematuria was similar in 5/6NE SHR and 5/6NE WKY rats. However, 5/6NE SHR had enlarged glomeruli, increased interstitial fibrosis, and prominent intimal thickening in the small arteries/arterioles as compared with 5/6NE WKY rats. CONCLUSIONS: The long-term severity of kidney injury correlated with higher blood pressure. Reduction of the kidney mass increases SCr, hematuria, proteinuria, and blood pressure in both normotensive and hypertensive rats. Histological assessment provides better information about underlying chronic kidney injury than actual changes in SCr and urinalysis.

Waldenström's macroglobulinemia masquerading as ovarian cancer with peritoneal carcinomatosis, ascites, and elevated CA-125.

Waldenström's macroglobulinemia is a rare hematology malignancy which often presents with "B symptoms," anemia, and thrombocytopenia. A 46-year-old woman presented with 2 months of abdominal distension accompanied by an unintentional 20-lb weight loss. Her abdominal CT scan demonstrated diffuse carcinomatosis with bilateral ovarian lesions and screening labs revealed a markedly elevated CA-125, suggesting a diagnosis of ovarian cancer. Upon admission for workup, patient was found to have a significant protein gap, later attributed to a markedly elevated IgM. Omental and bone marrow biopsy confirmed the diagnosis of Waldenström's macroglobulinemia, with elevation in CA-125 thought to be secondary to peritoneal irritation. This patient has since been successfully treated with six cycles of bendamusine and rituximab with no evidence of disease on staging scans and normalization of both CA-125 and IgM. To our knowledge, this is the first documented case of Waldenström's macroglobulinemia presenting with symptoms classically associated with ovarian cancer and demonstrates the importance of maintaining a broad differential when evaluating patients with abdominal carcinomatosis.

Anticoagulant-Related Nephropathy in Kidney Biopsy: A Single-Center Report of 41 Cases.

RATIONALE & OBJECTIVE: In 2009, the first case of acute kidney injury and occlusive red blood cell (RBC) tubular casts associated with a high international normalized ratio in a patient receiving warfarin was identified. This entity, named warfarin-related nephropathy, was later renamed anticoagulant-related nephropathy (ARN) after similar cases with other anticoagulants were described. We provide our 10-year experience with ARN based on a single-center kidney biopsy laboratory. STUDY DESIGN: The kidney pathology database at the Ohio State University Wexner Medical Center (OSUWMC) was searched for native kidney biopsy cases consistent with ARN. Clinical data were obtained from patient medical records. SETTING & PARTICIPANTS: Native kidney biopsies evaluated between January 1, 2009, and December 31, 2017 at OSUWMC. RESULTS: Among 8,636 native kidney biopsies reviewed at the OSUWMC, there were 41 (0.5%) patients for whom deterioration in kidney function could not be explained by kidney biopsy findings alone if anticoagulation was not considered. There were 63% men and 95% were white; average age was 62 ± 14 years. Most were on warfarin therapy (N = 28), although cases were also attributed to direct-acting anticoagulants (N = 2), antiplatelet medications (N = 1), heparin or enoxaparin (N = 4), and disseminated intravascular coagulopathy (N = 6). Morphologically, there was acute tubular necrosis and RBC casts. The majority of biopsies had an underlying glomerular disease and many patients had positive serologic test results. In all these cases, the severity of kidney failure, RBC tubular casts, and hematuria were disproportionate to glomerular morphologic changes. LIMITATIONS: Selection bias in the decision to perform a kidney biopsy. CONCLUSIONS: ARN is an uncommon diagnosis in kidney pathology practice, but it should be considered when the number of RBC tubular casts is disproportionate to the severity of glomerular changes in a kidney biopsy in patients either receiving anticoagulation therapy or who presented with acute coagulopathy. Our data suggest that anticoagulation aggravates underlying glomerular diseases rather than directly affecting the glomerular filtration barrier.

Erdheim Chester disease in a patient with Burkitt lymphoma: a case report and review of literature.

BACKGROUND: Erdheim Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis characterized by widespread tissue infiltration by CD68-positive, CD1a-negative foamy histiocytes. ECD can be difficult to identify, and diagnosis relies on the presence of histiocytes with certain histologic and immunophenotypic features in an appropriate clinical and radiologic setting. Clinical signs and symptoms are variable depending on which organ systems are involved. Most patients have at least skeletal involvement with bone pain as well as fatigue. Other common manifestations include diabetes insipidus, cardiac, periaortic, or retro-orbital infiltration/fibrosis, kidney impairment, xanthelasmas, among others. CASE PRESENTATION: Herein, we describe a case of BRAF-mutation positive ECD in a patient with Burkitt lymphoma, and we review recent literature. CONCLUSION: Underlying BRAF and other MAPK pathway mutations are identified in approximately 50% of cases of ECD, which aids in diagnosis as well as enables novel targeted treatments. ECD patients have an increased risk of myeloid neoplasms; however, unlike other histiocytoses, an association with lymphoproliferative disorders has not been recognized.

Acute glomerulonephritis with large confluent IgA-dominant deposits associated with liver cirrhosis.

BACKGROUND: Small glomerular IgA deposits have been reported in patients with liver cirrhosis, mainly as an incidental finding in autopsy studies. We recently encountered nine cirrhotic patients who presented with acute proliferative glomerulonephritis with unusually large, exuberant glomerular immune complex deposits, in the absence of systemic lupus erythematosus (SLE) or monoclonal gammopathy-related kidney disease. Deposits were typically IgA dominant/codominant. Our aim was to further elucidate the etiology, diagnostic pitfalls, and clinical outcomes. METHODS: We present clinical features and kidney biopsy findings of nine cirrhotic patients with an unusual acute immune complex glomerulonephritis. We also identified native kidney biopsies from all patients with liver cirrhosis at our institution over a 13-year period (January 2004 to December 2016) to evaluate presence of glomerular IgA deposits in them (n = 118). RESULTS: Six of nine cirrhotic patients with the large immune deposits had a recent/concurrent acute bacterial infection, prompting a diagnosis of infection-associated glomerulonephritis and treatment with antibiotics. In the remaining three patients, no infection was identified and corticosteroids were initiated. Three of nine patients recovered kidney function (one recovered kidney function after liver transplant); three patients developed chronic kidney disease but remained off dialysis; two patients became dialysis-dependent and one patient developed sepsis and expired shortly after biopsy. Within the total cohort of 118 patients with cirrhosis, 67 others also showed IgA deposits, albeit small; and 42 patients had no IgA deposits. CONCLUSIONS: These cases provide support to the theory that liver dysfunction may compromise clearance of circulating immune complexes, enabling deposition in the kidney. At least in a subset of cirrhotic patients, a superimposed bacterial infection may serve as a "second-hit" and lead to acute glomerulonephritis with exuberant immune complex deposits. Therefore, a trial of antibiotics is recommended and caution is advised before immunosuppressive treatment is offered. Unfortunately, most of these patients have advanced liver failure; therefore both diagnosis and management remain a challenge.

Histology of colorectal adenocarcinoma with double somatic mismatch-repair mutations is indistinguishable from those caused by Lynch syndrome.

Lynch syndrome (LS) is the most common form of hereditary colon cancer. Germline mutations in the mismatch-repair (MMR) genes MLH1, MSH2 (EPCAM), MSH6, and PMS2, followed by a second hit to the remaining allele, lead to cancer development. Universal tumor screening for LS is routinely performed on colon cancer, and screening has identified patients with unexplained MMR deficiency that lack MLH1 methylation and a germline mutation. Tumor sequencing has since identified double somatic (DS) mutations in the MMR gene corresponding with the absent protein in 69% of these patients. We assessed whether histomorphology could distinguish patients with DS mutations from those with LS. Colorectal cancer patients with DS mutations were identified from population-based cohorts from Iceland (2000-2009); Columbus, Ohio (1999-2005); and the state of Ohio (2013-2016). Next-generation sequencing was performed on tumors with unexplained MMR deficiency. Patients with LS from Ohio cohorts were the comparison group. The histologic features associated with MMR deficiency (tumor-infiltrating lymphocytes, Crohn-like reaction, histologic subtype, necrosis) were evaluated. We identified 43 tumors with DS mutations and 48 from patients with LS. There was no significant difference in histologic features between tumors in LS patients and tumors with DS mutations. Because histology of tumors with DS mutations is indistinguishable from those caused by LS, tumor sequencing for evaluation of DS mutations should be considered to help clarify sporadic versus hereditary causes of unexplained MMR deficiency.

BRAF V600E expression in histiocytic sarcoma associated with splenic marginal zone lymphoma: a case report.

BACKGROUND: Histiocytic sarcoma is a rare histiocytic neoplasm of unknown etiology that constitutes less than 1% of hematologic malignancies. A few cases of histiocytic sarcoma harboring the BRAF V600E mutation have been reported, but this finding has not been confirmed in all studies. CASE PRESENTATION: We report the case of a 63-year-old white woman with a history of splenic marginal zone lymphoma who presented with 2 weeks of right-sided neck swelling. Positron emission tomography revealed an intensely hypermetabolic and destructive soft tissue mass in her right skull base. A bone marrow biopsy was performed, which revealed an infiltrate of malignant cells characterized as large pleomorphic cells with frequent folded/irregular nuclei, variably prominent nucleoli, fine chromatin, and abundant amounts of eosinophilic cytoplasm. The malignant cells were positive for CD163, CD68 (granular), lysozyme (granular), CD4, and CD45 (partial). Based on the biopsy findings, she was diagnosed as having histiocytic sarcoma. The malignant cells tested positive for the BRAFV600E protein using immunohistochemistry. Before treatment of her histiocytic sarcoma could be initiated, she developed disseminated intravascular coagulation and acute hypoxemic respiratory failure secondary to non-cardiogenic pulmonary edema. She decided to pursue comfort care and died in our hospital 2 weeks following admission. CONCLUSIONS: Our case illustrates the aggressive nature of histiocytic sarcoma, and provides rare evidence that histiocytic sarcoma associated with indolent lymphomas may harbor the BRAF V600E mutation. Further research is needed to clarify the role of targeted therapies such as vemurafenib in the treatment of patients with this disorder.

The Severity of Intracranial Hemorrhages Measured by Free Hemoglobin in the Brain Depends on the Anticoagulant Class: Experimental Data.

Background and Purpose. Anticoagulant therapy is broadly used to prevent thromboembolic events. Intracranial hemorrhages are serious complications of anticoagulation, especially with warfarin. Direct oral anticoagulants reduce but do not eliminate the risk of intracranial hemorrhages. The aim of this study is to determine the degree of intracranial hemorrhage after application of anticoagulants without additional triggers. Methods. Rats were treated with different anticoagulant classes (vitamin K antagonists, heparin, direct thrombin inhibitor, and factor Xa inhibitor). Brain hemorrhages were assessed by the free hemoglobin concentration in the brain parenchyma. Results. Vitamin K antagonists (warfarin and brodifacoum) significantly increased free hemoglobin in the brain. Among direct oral anticoagulants, thrombin inhibitor dabigatran also significantly increased free hemoglobin in the brain, whereas treatment with factor Xa inhibitor rivaroxaban did not have significant effect on the free hemoglobin concentration. Conclusions. Our data indicates that the severity of brain hemorrhages depends on the anticoagulant class and it is more pronounced with vitamin K antagonists.