Non-IG::MYC in diffuse large B-cell lymphoma confers variable genomic configurations and MYC transactivation potential.

MYC translocation occurs in 8-14% of diffuse large B-cell lymphoma (DLBCL), and may concur with BCL2 and/or BCL6 translocation, known as double-hit (DH) or triple-hit (TH). DLBCL-MYC/BCL2-DH/TH are largely germinal centre B-cell like subtype, but show variable clinical outcome, with IG::MYC fusion significantly associated with inferior survival. While DLBCL-MYC/BCL6-DH are variable in their cell-of-origin subtypes and clinical outcome. Intriguingly, only 40-50% of DLBCL with MYC translocation show high MYC protein expression (>70%). We studied 186 DLBCLs with MYC translocation including 32 MYC/BCL2/BCL6-TH, 75 MYC/BCL2-DH and 26 MYC/BCL6-DH. FISH revealed a MYC/BCL6 fusion in 59% of DLBCL-MYC/BCL2/BCL6-TH and 27% of DLBCL-MYC/BCL6-DH. Targeted NGS showed a similar mutation profile and LymphGen genetic subtype between DLBCL-MYC/BCL2/BCL6-TH and DLBCL-MYC/BCL2-DH, but variable LymphGen subtypes among DLBCL-MYC/BCL6-DH. MYC protein expression is uniformly high in DLBCL with IG::MYC, but variable in those with non-IG::MYC including MYC/BCL6-fusion. Translocation breakpoint analyses of 8 cases by TLC-based NGS showed no obvious genomic configuration that enables MYC transactivation in 3 of the 4 cases with non-IG::MYC, while a typical promoter substitution or IGH super enhancer juxtaposition in the remaining cases. The findings potentially explain variable MYC expression in DLBCL with MYC translocation, and also bear practical implications in its routine assessment.

Technical note on the exploration of COVID-19 in autopsy material.

Interrogation of immune response in autopsy material from patients with SARS-CoV-2 is potentially significant. We aim to describe a validated protocol for the exploration of the molecular physiopathology of SARS-CoV-2 pulmonary disease using multiplex immunofluorescence (mIF).The application of validated assays for the detection of SARS-CoV-2 in tissues, originally developed in our laboratory in the context of oncology, was used to map the topography and complexity of the adaptive immune response at protein and mRNA levels.SARS-CoV-2 is detectable in situ by protein or mRNA, with a sensitivity that could be in part related to disease stage. In formalin-fixed, paraffin-embedded pneumonia material, multiplex immunofluorescent panels are robust, reliable and quantifiable and can detect topographic variations in inflammation related to pathological processes.Clinical autopsies have relevance in understanding diseases of unknown/complex pathophysiology. In particular, autopsy materials are suitable for the detection of SARS-CoV-2 and for the topographic description of the complex tissue-based immune response using mIF.

Contribution of immunoglobulin lambda light chain gene rearrangement analysis in the diagnosis of B-cell neoplasms.

Identification of clonal IGH, IGK and IGL gene rearrangements offers diagnostic adjunct in suspected B-cell neoplasms. However, many centres omit IGL analysis as its value is uncertain. A review of 567 cases with IGH, IGK and IGL rearrangement assessed using BIOMED-2 assays showed clonal immunoglobulin gene rearrangement in 54% of cases, of which 24% had a clonal IGL rearrangement. In two cases, the clonal rearrangement was detected exclusively by IGL analysis. This finding demonstrates the added value of IGL analysis for clonality assessment, especially in suspected B-cell neoplasms in which a clonal IGH and/or IGK rearrangement is not detected or is equivocal.

Case 243: Extramedullary Hematopoiesis in an Adrenal Myelolipoma.

History A 30-year-old man presented to the emergency department with epigastric pain. He was vomiting and in distress, and he had a history of thalassemia. Physical examination findings were unremarkable. Pertinent blood results were a hemoglobin level of 10.5 g/dL (6.52 mmol/L) (normal range, 13.5-18.0 g/dL [8.38-11.17 mmol/L]) and a bilirubin level of 62 µmol/L (normal range, 3-17 µmol/L). The remaining hematologic and biochemical results were normal. Aortic dissection was suspected clinically, so the patient was referred for imaging. Unenhanced and arterial phase computed tomographic (CT) images were acquired initially. Ultrasonography (US) (images not shown) and magnetic resonance (MR) imaging were performed subsequently. Because of the imaging findings, the patient was referred for surgery.

Validation of digital pathology imaging for primary histopathological diagnosis.

AIMS: Digital pathology (DP) offers advantages over glass slide microscopy (GS), but data demonstrating a statistically valid equivalent (i.e. non-inferior) performance of DP against GS are required to permit its use in diagnosis. The aim of this study is to provide evidence of non-inferiority. METHODS AND RESULTS: Seventeen pathologists re-reported 3017 cases by DP. Of these, 1009 were re-reported by the same pathologist, and 2008 by a different pathologist. Re-examination of 10 138 scanned slides (2.22 terabytes) produced 72 variances between GS and DP reports, including 21 clinically significant variances. Ground truth lay with GS in 12 cases and with DP in nine cases. These results are within the 95% confidence interval for existing intraobserver and interobserver variability, proving that DP is non-inferior to GS. In three cases, the digital platform was deemed to be responsible for the variance, including a gastric biopsy, where Helicobacter pylori only became visible on slides scanned at the ×60 setting, and a bronchial biopsy and penile biopsy, where dysplasia was reported on DP but was not present on GS. CONCLUSIONS: This is one of the largest studies proving that DP is equivalent to GS for the diagnosis of histopathology specimens. Error rates are similar in both platforms, although some problems e.g. detection of bacteria, are predictable.

HyMaP: A hybrid magnitude-phase approach to unsupervised segmentation of tumor areas in breast cancer histology images.

BACKGROUND: Segmentation of areas containing tumor cells in standard H&E histopathology images of breast (and several other tissues) is a key task for computer-assisted assessment and grading of histopathology slides. Good segmentation of tumor regions is also vital for automated scoring of immunohistochemical stained slides to restrict the scoring or analysis to areas containing tumor cells only and avoid potentially misleading results from analysis of stromal regions. Furthermore, detection of mitotic cells is critical for calculating key measures such as mitotic index; a key criteria for grading several types of cancers including breast cancer. We show that tumor segmentation can allow detection and quantification of mitotic cells from the standard H&E slides with a high degree of accuracy without need for special stains, in turn making the whole process more cost-effective. METHOD: BASED ON THE TISSUE MORPHOLOGY, BREAST HISTOLOGY IMAGE CONTENTS CAN BE DIVIDED INTO FOUR REGIONS: Tumor, Hypocellular Stroma (HypoCS), Hypercellular Stroma (HyperCS), and tissue fat (Background). Background is removed during the preprocessing stage on the basis of color thresholding, while HypoCS and HyperCS regions are segmented by calculating features using magnitude and phase spectra in the frequency domain, respectively, and performing unsupervised segmentation on these features. RESULTS: All images in the database were hand segmented by two expert pathologists. The algorithms considered here are evaluated on three pixel-wise accuracy measures: precision, recall, and F1-Score. The segmentation results obtained by combining HypoCS and HyperCS yield high F1-Score of 0.86 and 0.89 with re-spect to the ground truth. CONCLUSIONS: In this paper, we show that segmentation of breast histopathology image into hypocellular stroma and hypercellular stroma can be achieved using magnitude and phase spectra in the frequency domain. The segmentation leads to demarcation of tumor margins leading to improved accuracy of mitotic cell detection.

Cutaneous telangiectasia and cauda equina syndrome: a presentation of diffuse large B-cell lymphoma.

We describe a 72-year-old woman with striking cutaneous telangiectatic lesions that chronologically preceded presentation with cauda equina syndrome. Diffuse large B-cell lymphoma (DLBCL) was confirmed on skin biopsies from plaques on the abdominal wall and left ankle, the possibilities including primary cutaneous DLBCL leg-type or systemic DLBCL. We speculate that this clinical appearance may arise due to lymphatic or vascular congestion resulting from the dense lymphoid infiltrate in this case.

Hemophagocytic lymphohistiocytosis in a patient with angioimmunoblastic lymphoma: a case report and review of the literature.

Hemophagocytic lymphohistiocytosis is a rare disorder characterized by a proliferation of phagocytic histiocytes in hematopoietic organs. It is accompanied by systemic manifestations and frequently has an abrupt onset with a fulminant clinical course and high mortality. Awareness of this condition is important since early diagnosis and initiation of treatment is critical for a successful outcome. The authors report a patient with hemophagocytic lymphohistiocytosis associated with angioimmunoblastic lymphoma, describe the clinical and histological features of hemophagocytic lymphohistiocytosis, and review the literature on this condition.

Evaluation of nipple discharge cytology and diagnostic value of red blood cells in cases with negative cytology: a cytohistologic correlation.

OBJECTIVE: To evaluate the sensitivity and specificity of nipple discharge cytology and to determine the diagnostic value of the presence of red blood cells (RBCs) in cases with negative cytology. STUDY DESIGN: Samples were received either as air-dried or alcohol-fixed slides. All cytology cases were reported by cytopathologists in the Hammersmith Pathology Department. RESULTS: We identified 98 consecutive female patients with nipple discharge cytology in the Hammersmith and Charing Cross hospitals during the period of May 2007 to May 2009. The cytodiagnoses were as follows: 86 cases had negative cytology, 9 cases were C3 (atypia but likely benign), and 3 cases were suspicious for or consistent with malignancy. Thirty of these cases had subsequent biopsy and showed: 9 benign cases, 3 cases with atypical papilloma and 3 cases with a malignant diagnosis (in situ and/or invasive ductal carcinoma). All suspicious and malignant cases with available macroscopic description (whether positive or negative on nipple discharge cytology) were blood stained and on microscopy contained RBCs. CONCLUSION: Nipple discharge cytology is a useful method in the diagnosis of malignant and suspicious cases. Further evaluation is needed to assess the value of the presence of RBCs in cases with negative cytology and its correlation with a subsequent diagnosis of malignancy.

Follicular dendritic cells in multicentric Castleman disease present human herpes virus type 8 (HHV8)-latent nuclear antigen 1 (LANA1) in a proportion of cases and is associated with an enhanced T-cell response.

Multicentric Castleman disease (MCD) is a rare human herpes virus type 8 (HHV8)-associated lymphoproliferative disorder that occurs more frequently in patients infected with human immunodeficiency virus (HIV). In tissue samples, HHV8-infected plasmablasts localise to the mantle zones of the lymphoid follicles. We revisited the immunohistological features in 25 lymph node (LN) and three spleen samples of MCD. In five (20%) LN and one (33%) spleen sample, HHV8 latent nuclear antigen 1 (LANA1) staining was also noted on the follicular dendritic cells (FDC). The HHV8-positive FDC subgroup of patients had significantly higher numbers of CD3-positive T cells infiltrating the follicles when compared to the HHV8-negative FDC subgroup (P = 0.047). Furthermore, the numbers of HHV8-positive plasmablasts and serum HHV8 viral copy numbers were lower among the HHV8-positive FDC subgroup when compared to the HHV8-negative FDC subgroup (not statistically significant). Our findings show, for the first time, possible 'presentation' of an HHV8 antigen by FDCs in MCD.

EBUS-TBNA for the clarification of PET positive intra-thoracic lymph nodes-an international multi-centre experience.

INTRODUCTION: To determine the sensitivity and accuracy of endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) for clarification of the nature of fluorodeoxyglucose-positron emission tomography (FDG) positive hilar and/or mediastinal lymph nodes in patients with (suspected) lung cancer. METHODS: All consecutive patients who had undergone EBUS-TBNA alone for assessment of abnormal FDG-uptake in hilar and/or mediastinal lymph nodes between January 2005 and August 2007 were reviewed. RESULTS: One-hundred-nine patients underwent EBUS-TBNA of 127 positron emission tomography positive lymph nodes. Hilar (station 10 or 11) nodes (N1 or N3) were aspirated in 26 patients and mediastinal (stations 2, 4, 7) nodes (N2 or N3) in 90 patients. In 7 patients both hilar and mediastinal nodes were sampled. There were no procedure-related complications. Malignancy was detected in 77 (71%) cases. Thirty-two patients were tumor negative by EBUS-TBNA; subsequent surgical biopsy in 19 showed malignancy in 7. In four cases the false negative result was due to sampling error and in three cases due to detection error. In 13 cases surgical staging was not performed although long term follow-up in 3 showed no evidence of malignancy. The sensitivity and accuracy of EBUS-TBNA for malignancy in patients with reference pathology was 91% and 92%, respectively. The negative predictive value was 60%. If the 10 cases for which confirmatory surgical staging was not performed are assumed to be false negative results, overall sensitivity and accuracy were 82% and 84%, respectively. CONCLUSIONS: EBUS-TBNA offers an effective accurate, minimally invasive strategy for evaluating FDG avid hilar and mediastinal lymph nodes. However, negative findings should be confirmed by surgical staging.

Telomerase inhibition and telomere targeting in hematopoietic cancer cell lines with small non-nucleosidic synthetic compounds (BIBR1532).

Telomere maintenance has been shown to be essential for unlimited growth potential of human cells and is regarded as one hallmark of cancer. Telomere repeats at the ends of eukaryotic chromosomes are synthesized by the enzyme telomerase, which is active in most cancers and to some extend also in normal somatic cells. Therefore, targeting the telomerase/telomere complex offers great potential for the development of novel anticancer therapeutics. An example of such a strategy is the small molecule BIBR1532 that is a selective, non-nucleosidic inhibitor of the catalytic component hTERT. Treatment of cancer cells with this compound leads to progressive telomere shortening, consecutive telomere dysfunction, and finally growth arrest after a lag period that is largely dependent on initial telomere length. We have additionally shown that using this class of telomerase inhibitor at higher concentrations exerts a direct cytotoxic effect on malignant cells of the hematopoietic system but not on normal stem cells, which appears to derive from direct damage to the structure of individual telomeres.

Selective cytotoxicity and telomere damage in leukemia cells using the telomerase inhibitor BIBR1532.

Telomerase represents an attractive target for a mechanism-based therapeutic approach because its activation has been associated with unlimited proliferation in most cancer cells. Recently, a nonnucleosidic small molecule inhibitor, BIBR1532 (2-[(E)-3-naphtalen-2-yl-but-2-enoylamino]-benzoic acid), has been identified that is highly selective for inhibition of telomerase, resulting in delayed growth arrest of tumor cells. Here we examined the effects of BIBR1532 in different leukemia cell lines as well as in primary cells from patients with acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL) in short-term culture assays. We observed a dose-dependent direct cytotoxicity in concentrations ranging from 30 to 80 microM. Interestingly, cell death was not dependent on the catalytic activity of telomerase but was delayed in cells with very long telomeres. We observed time-dependent individual telomere erosion, which was associated with loss of telomeric repeat binding factor 2 (TRF2) and increased phosphorylation of p53. Importantly, the proliferative capacity of normal CD34(+) cells from cord blood and leukapheresis samples was not affected by treatment with BIBR1532. We conclude that using this class of telomerase inhibitor at higher concentrations exerts a direct cytotoxic effect on malignant cells of the hematopoietic system, which appears to derive from direct damage of the structure of individual telomeres and must be dissected from telomerase-suppressed overall telomere shortening.