Laryngeal mucous membrane plasmacytosis with 15 year follow-up: Case report and literature review.

Mucous membrane plasmacytosis (MMP) is an uncommon variant of mucositis represented by a polyclonal plasma cell infiltration of mucosal tissue. Various clinical presentations in the upper airway have been reported ranging from erythematous mucosa to fungating masses. Histologic features include mucosal epithelial hyperplasia or psoriasiform changes with a dense submucosal infiltrate of polytypic plasma cells. Molecular studies for immunoglobulin gene rearrangement should be performed in all cases of MMP to rule out clonal neoplastic expansion of plasma cells. We present a case of MMP with over 15 years of clinical follow-up, emphasizing the relatively benign clinical course of this disorder.

Somatic molecular analysis augments cytologic evaluation of pancreatic cyst fluids as a diagnostic tool.

Objective: Better tools are needed for early diagnosis and classification of pancreatic cystic lesions (PCL) to trigger intervention before neoplastic precursor lesions progress to adenocarcinoma. We evaluated the capacity of molecular analysis to improve the accuracy of cytologic diagnosis for PCL with an emphasis on non-diagnostic/negative specimens. Design: In a span of 7 years, at a tertiary care hospital, 318 PCL endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) were evaluated by cytologic examination and molecular analysis. Mucinous PCL were identified based on a clinical algorithm and 46 surgical resections were used to verify this approach. The mutation allele frequency (MAF) of commonly altered genes (BRAF, CDKN2A, CTNNB1, GNAS, RAS, PIK3CA, PTEN, SMAD4, TP53 and VHL) was evaluated for their ability to identify and grade mucinous PCL. Results: Cytology showed a diagnostic sensitivity of 43.5% for mucinous PCL due in part to the impact of non-diagnostic (28.8%) and negative (50.5%) specimens. Incorporating an algorithmic approach or molecular analysis markedly increased the accuracy of cytologic evaluation. Detection of mucinous PCL by molecular analysis was 93.3% based on the detection of KRAS and/or GNAS gene mutations (p = 0.0001). Additional genes provided a marginal improvement in sensitivity but were associated with cyst type (e.g. VHL) and grade (e.g. SMAD4). In the surgical cohort, molecular analysis and the proposed algorithm showed comparable sensitivity (88.9% vs. 100%). Conclusions: Incorporating somatic molecular analysis in the cytologic evaluation of EUS-FNA increases diagnostic accuracy for detection, classification and grading of PCL. This approach has the potential to improve patient management.

Next-Generation Sequencing to Detect Deletion of RB1 and ERBB4 Genes in Chromophobe Renal Cell Carcinoma: A Potential Role in Distinguishing Chromophobe Renal Cell Carcinoma from Renal Oncocytoma.

Overlapping morphologic, immunohistochemical, and ultrastructural features make it difficult to diagnose chromophobe renal cell carcinoma (ChRCC) and renal oncocytoma (RO). Because ChRCC is a malignant tumor, whereas RO is a tumor with benign behavior, it is important to distinguish these two entities. We aimed to identify genetic markers that distinguish ChRCC from RO by using next-generation sequencing (NGS). NGS for hotspot mutations or gene copy number changes was performed on 12 renal neoplasms, including seven ChRCC and five RO cases. Matched normal tissues from the same patients were used to exclude germline variants. Rare hotspot mutations were found in cancer-critical genes (TP53 and PIK3CA) in ChRCC but not RO. The NGS gene copy number analysis revealed multiple abnormalities. The two most common deletions were tumor-suppressor genes RB1 and ERBB4 in ChRCC but not RO. Fluorescence in situ hybridization was performed on 65 cases (ChRCC, n = 33; RO, n = 32) to verify hemizygous deletion of RB1 (17/33, 52%) or ERBB4 (11/33, 33%) in ChRCC, but not in RO (0/32, 0%). In total, ChRCCs (23/33, 70%) carry either a hemizygous deletion of RB1 or ERBB4. The combined use of RB1 and ERBB4 fluorescence in situ hybridization to detect deletion of these genes may offer a highly sensitive and specific assay to distinguish ChRCC from RO.

Phosphorylation of the Mdm2 oncoprotein by the c-Abl tyrosine kinase regulates p53 tumor suppression and the radiosensitivity of mice.

The p53 tumor suppressor acts as a guardian of the genome by preventing the propagation of DNA damage-induced breaks and mutations to subsequent generations of cells. We have previously shown that phosphorylation of the Mdm2 oncoprotein at Ser394 by the ATM kinase is required for robust p53 stabilization and activation in cells treated with ionizing radiation, and that loss of Mdm2 Ser394 phosphorylation leads to spontaneous tumorigenesis and radioresistance in Mdm2S394A mice. Previous in vitro data indicate that the c-Abl kinase phosphorylates Mdm2 at the neighboring residue (Tyr393) in response to DNA damage to regulate p53-dependent apoptosis. In this present study, we have generated an Mdm2 mutant mouse (Mdm2Y393F) to determine whether c-Abl phosphorylation of Mdm2 regulates the p53-mediated DNA damage response or p53 tumor suppression in vivo. The Mdm2Y393F mice develop accelerated spontaneous and oncogene-induced tumors, yet display no defects in p53 stabilization and activity following acute genotoxic stress. Although apoptosis is unaltered in these mice, they recover more rapidly from radiation-induced bone marrow ablation and are more resistant to whole-body radiation-induced lethality. These data reveal an in vivo role for c-Abl phosphorylation of Mdm2 in regulation of p53 tumor suppression and bone marrow failure. However, c-Abl phosphorylation of Mdm2 Tyr393 appears to play a lesser role in governing Mdm2-p53 signaling than ATM phosphorylation of Mdm2 Ser394. Furthermore, the effects of these phosphorylation events on p53 regulation are not additive, as Mdm2Y393F/S394A mice and Mdm2S394A mice display similar phenotypes.

PD-L1 expression in EBV-negative diffuse large B-cell lymphoma: clinicopathologic features and prognostic implications.

Programmed cell death ligand 1 (PD-L1) is a cell surface glycoprotein that regulates the cellular immune response and serves as a targetable immune checkpoint molecule. PD-L1 is expressed on tumor cells and the immune microenvironment of several human malignancies, including a subset of aggressive lymphomas. We sought to investigate further the clinical and pathologic features of EBV-negative diffuse large B-cell lymphoma (DLBCL) cases that express PD-L1. Immunohistochemical staining using an anti-PD-L1 monoclonal antibody was performed on DLBCL cases from 86 patients. These patients received standard chemotherapy treatment and were followed for up to 175 months. Overall, 14 cases (16%) were considered positive for PD-L1 in tumor cells. In comparison with PD-L1 negative cases, PD-L1 positive cases had a higher rate of non-GCB type (71% vs. 30%, P=0.0060), and higher Ann Arbor stage (II-IV) (100% vs. 73%, P=0.0327). No significant differences were seen in the immunohistochemical expression of BCL2, MYC, or Ki67. Patients with tumors expressing PD-L1 demonstrated inferior overall survival (OS) upon long term follow up (P=0.0447). Both age/sex-adjusted and multivariate analyses identified PD-L1 as an independent predictor for OS (P=0.0101 and P=0.0424). There was no significant difference, however, in terms of remission rates after first treatment, relapse rates, and progression free survival between the groups. Identification of DLBCL cases that express PD-L1 may serve to select a subset of patients that could further benefit from targeted immunotherapy.

Immunohistochemical loss of 5-hydroxymethylcytosine expression in acute myeloid leukaemia: relationship to somatic gene mutations affecting epigenetic pathways.

AIMS: Genes affecting epigenetic pathways are frequently mutated in myeloid malignancies, including acute myeloid leukaemia (AML). The genes encoding TET2, IDH1 and IDH2 are among the most commonly mutated genes, and cause defective conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5hmC), impairing demethylation of DNA, and presumably serving as driver mutations in leukaemogenesis. The aim of this study was to correlate 5hmC immunohistochemical loss with the mutation status of genes involved in epigenetic pathways in AML. METHODS AND RESULTS: Immunohistochemical staining with an anti-5hmC antibody was performed on 41 decalcified, formalin-fixed paraffin-embedded (FFPE) bone marrow biopsies from patients with AML. Archived DNA was subjected to next-generation sequencing for analysis of a panel of genes, including TET2, IDH1, IDH2, WT1 and DNMT3A. TET2, IDH1, IDH2, WT1 and DNMT3A mutations were found in 46% (19/41) of the cases. Ten of 15 cases (67%) with TET2, IDH1, IDH2 or WT1 mutations showed deficient 5hmC staining, whereas nine of 26 cases (35%) without a mutation in these genes showed loss of 5hmC. It is of note that all four cases with TET2 mutations showed deficient 5hmC staining. CONCLUSIONS: Overall, somatic mutations in TET2, IDH1, IDH2, WT1 and DNMT3A were common in our cohort of AML cases. Immunohistochemical staining for 5hmC was lost in the majority of cases harbouring mutations in these genes, reflecting the proposed relationship between dysfunctional epigenetic pathways and leukaemogenesis.

Role of Tetrasomy for the Diagnosis of Urothelial Carcinoma Using UroVysion Fluorescent In Situ Hybridization.

CONTEXT: -UroVysion fluorescent in situ hybridization (FISH) is routinely used to detect urothelial carcinoma (UC). A positive threshold is defined as chromosome polysomy in 4 or more cells, which also includes tetrasomy, a natural product of cell division. OBJECTIVES: -To evaluate tetrasomy for UC detection and explore the relation to the surgical diagnosis or patient history. DESIGN: -The FISH was performed on 1532 urine samples from patients with cytology results and 4 or more years of follow-up. We created separate polysomy and tetrasomy categories and constructed receiver operating curves to determine appropriate thresholds using biopsy (n = 194) as the gold standard. Standard FISH and a novel assay integrating cytomorphology and FISH (Target-FISH) were compared. Matching tissue biopsies of urine samples with 10 or more tetrasomy cells were analyzed. RESULTS: -No significant threshold was found for tetrasomy cells. Exclusion of tetrasomy from the polysomy category changed the threshold from 8.5 to 4.5 cells, increased specificity (59.2% to 78.9%), but reduced sensitivity (78.9% to 65.9%). In Target-FISH, the same approach yielded a specificity of 93.7% and sensitivity of 65.2%. Similarly, specificity improved significantly for low- and high-grade UC, but sensitivity decreased for low-grade UC. No evidence of UC was observed in 95% (52 of 55) of the patients referred for screening who had 10 or more tetrasomy cells by FISH. Matching biopsies for urines containing 10 or more tetrasomy cells showed few or no tetrasomy cells. CONCLUSIONS: -Tetrasomy is a nonspecific finding frequently encountered in urine FISH and should be excluded from the polysomy classification. Target-FISH is an optimal approach, offering the ability to detect rare tetrasomy tumors.

Mild Microcytic Anemia in an Infant with a Compound Heterozygosity for Hb C (HBB: c.19G > A) and Hb Osu Christiansborg (HBB: c.157G > A).

We report an infant with a compound heterozygosity for Hb C (HBB: c.19G > A) and Hb Osu Christiansborg (HBB: c.157G > A) and a phenotype of mild microcytic anemia with target cell morphology but without overt hemolysis.

MYC Immunohistochemistry to Identify MYC-Driven B-Cell Lymphomas in Clinical Practice.

OBJECTIVES: Immunohistochemistry with anti-MYC antibody (MYC IHC) detects MYC protein in fixed samples of aggressive B-cell lymphomas and, according to the number of positive staining tumor nuclei, facilitates tumor subclassification, predicts underlying MYC rearrangements, and stratifies patient outcome. We aimed to determine the performance of MYC IHC in clinical practice. METHODS: We reviewed MYC IHC performed on control specimens and 256 aggressive B-cell lymphomas and compared clinically reported IHC scores with experts' review. RESULTS: Control tissues showed less than 5% variation in daily IHC staining. Reported and expert IHC scores were well correlated (r = 0.86) with an SD of 14.2%. Reported IHC scores 30% or less and 70% or more were accurate (94.5%) compared with experts in categorizing tumors as "MYC IHC-Low" and "MYC IHC-High," respectively, but scores 40% to 60% were not (60.3%). The mean IHC score among lymphomas with MYC rearrangements was 80%, but with a large range of scores (20%-100%). There was no statistically significant association between IHC score and MYC copy number. CONCLUSIONS: Under optimal conditions, clinically reported MYC IHC scores are concordant with expert scores within 15%. MYC IHC does not capture all B-cell lymphomas with MYC rearrangements, however. MYC IHC and MYC fluorescence in situ hybridization are both recommended to identify MYC-driven B-cell lymphomas.

Hemophagocytic lymphohistiocytosis secondary to T-cell/histiocyte-rich large B-cell lymphoma.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening clinical syndrome characterized by dysregulation of the immune system. Impaired function of cytotoxic T cells and natural killer cells is often seen, and T-cell malignancies represent most cases of lymphoma-associated HLH. HLH associated with B-cell lymphoma is rare. We describe a case of a 30-year-old man who presented with fever, splenomegaly, and hyperferritinemia. Bone marrow biopsy revealed T-cell/histiocyte-rich large B-cell lymphoma, a rare, aggressive B-cell malignancy. This case highlights the interplay between a pro-inflammatory cytokine microenvironment and tumor-mediated immune suppression, and addresses the importance of accurately diagnosing these entities for appropriate clinical management.

IMP3 expression is associated with poor outcome and epigenetic deregulation in intrahepatic cholangiocarcinoma.

IMP3 is a fetal protein not expressed in normal adult tissues. IMP3 is an oncoprotein and a useful biomarker for a variety of malignancies and is associated with reduced overall survival of a number of them. IMP3 expression and its prognostic value for patients with intrahepatic cholangiocarcinoma (ICC) have not been well investigated. The molecular mechanism underlying IMP3 expression in human cancer cells remains to be elucidated. Here we investigated IMP3 expression in ICC and adjacent nonneoplastic liver in 72 unifocal primary ICCs from a single institute by immunohistochemistry, immunoblotting, and real-time polymerase chain reaction. IMP3 was specifically expressed in cancer cells but not in the surrounding normal tissue, and 59 (82%) of 72 ICCs were IMP3 positive by immunohistochemistry. Among 35 cases with lymphovascular invasion, 26 (74%) showed IMP3 positivity in lymph node metastases. IMP3 expression was significantly correlated with tumor size, pathological grade, metastasis, and clinical stage. Kaplan-Meier analysis demonstrated an inverse correlation between IMP3 expression and overall survival rate. Multivariate analysis revealed that IMP3 was the only risk factor associated with survival. To further explore the mechanism of IMP3 expression in cancers, we identified 2 CpG islands at IMP3 proximal promoter. Interestingly, the IMP3 promoter was almost completely demethylated in ICCs in contrast to densely methylated promoter in normal liver tissues. IMP3 expression is a useful biomarker for ICCs and can provide an independent prognostic value for patients with ICC. To our knoweldge, this is the first direct evidence of epigenetic deregulation of IMP3 in human cancer.

MYC protein expression is detected in plasma cell myeloma but not in monoclonal gammopathy of undetermined significance (MGUS).

It has been recognized that monoclonal gammopathy of undetermined significance (MGUS) precedes a diagnosis of plasma cell myeloma in most patients. Recent gene expression array analysis has revealed that an MYC activation signature is detected in plasma cell myeloma but not in MGUS. In this study, we performed immunohistochemical studies using membrane CD138 and nuclear MYC double staining on bone marrow biopsies from patients who met the diagnostic criteria of plasma cell myeloma or MGUS. Our study demonstrated nuclear MYC expression in CD138-positive plasma cells in 22 of 26 (84%) plasma cell myeloma samples and in none of the 29 bone marrow samples from patients with MGUS. In addition, our data on the follow-up biopsies from plasma cell myeloma patients with high MYC expression demonstrated that evaluation of MYC expression in plasma cells can be useful in detecting residual disease. We also demonstrated that plasma cells gained MYC expression in 5 of 8 patients (62.5%) when progressing from MGUS to plasma cell myeloma. Analysis of additional lymphomas with plasmacytic differentiation, including lymphoplasmacytic lymphoma, marginal zone lymphoma, and plasmablastic lymphoma, reveals that MYC detection can be a useful tool in the diagnosis of plasma cell myeloma.

Oncofetal protein IMP3, a new cancer biomarker.

IMP3 is a member of a family of RNA-binding proteins that consists of IMP1, IMP2 and IMP3. These proteins contain 2 RNA recognition motifs and 4 K-homology domains that allow them to bind RNAs strongly and specifically. IMP3 is an oncofetal protein involved in embryogenesis and its expression is associated with a number of malignant neoplasms. IMP3 is associated with aggressive and advanced cancers and is specifically expressed in malignant tumors but is not found in adjacent benign tissues. Moreover, in vitro studies have shown that IMP3 promotes tumor cell proliferation, adhesion, and invasion. This review focuses on the studies of IMP3 expression in different cancers and emphasizes the potential utility of IMP3 in routine surgical pathology practice. We also discuss IMP3 as a prognostic biomarker for cancer patients' outcomes.

Five important advances in hematopathology.

CONTEXT: Hematopathology is a dynamic field that has always been on the frontier of clinical research within the scope of pathology. Several recent developments in hematopathology will likely affect its practice clinically. OBJECTIVE: To review 5 important recent advances in hematopathology: (1) detection and prognostic implication of MYC in diffuse large B-cell lymphomas, (2) determining origin and prognosis through immunoglobulin gene usage in mature B-cell neoplasms, (3)detecting minimal residual disease in multiple myeloma, (4) using genome-wide analysis in myelodysplastic syndromes, and (5) employing whole-genome sequencing in acute myeloid leukemias. DATA SOURCES: Literature review and the authors' experiences in an academic center. CONCLUSIONS: These advances will bring hematopathology into a new molecular era and help us to better understand the molecular, pathologic mechanisms of lymphomas, leukemias, myelomas, and myelodysplastic syndromes. They will help us to identify diagnostic and prognostic markers and eventually provide new therapeutic targets and treatments for these diseases.

Loss of 5-hydroxymethylcytosine correlates with increasing morphologic dysplasia in melanocytic tumors.

DNA methylation is the most well-studied epigenetic modification in cancer biology. 5-hydroxymethylcytosine is an epigenetic mark that can be converted from 5-methylcytosine by the ten-eleven translocation gene family. We recently reported the loss of 5-hydroxymethylcytosine in melanoma compared with benign nevi and suggested that loss of this epigenetic marker is correlated with tumor virulence based on its association with a worse prognosis. In this study, we further characterize the immunoreactivity patterns of 5-hydroxymethylcytosine in the full spectrum of melanocytic lesions to further validate the potential practical application of this epigenetic marker. One hundred and seventy-five cases were evaluated: 18 benign nevi, 20 dysplastic nevi (10 low-grade and 10 high-grade lesions), 10 atypical Spitz nevi, 20 borderline tumors, 5 melanomas arising within nevi, and 102 primary melanomas. Progressive loss of 5-hydroxymethylcytosine from benign dermal nevi to high-grade dysplastic nevi to borderline melanocytic neoplasms to melanoma was observed. In addition, an analysis of the relationship of nuclear diameter with 5-hydroxymethylcytosine staining intensity within lesional cells revealed a significant correlation between larger nuclear diameter and decreased levels of 5-hydroxymethylcytosine. Furthermore, borderline lesions uniquely exhibited a diverse spectrum of staining of each individual case. This study further substantiates the association of 5-hydroxymethylcytosine loss with dysplastic cytomorphologic features and tumor progression and supports the classification of borderline lesions as a biologically distinct category of melanocytic lesions.

Advances in understanding the pathogenesis of HLH.

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory disorder resulting from immune dysfunction reflecting either primary immune deficiency or acquired failure of normal immune homeostasis. Familial HLH includes autosomal recessive and X-linked disorders characterized by uncontrolled activation of T cells and macrophages and overproduction of inflammatory cytokines, secondary to defects in genes encoding proteins involved in granule-dependent cytolytic pathways. In older children and adults, HLH is associated more often with infections, malignancies, autoimmune diseases, and acquired immune deficiencies. HLH, macrophage activation syndrome, sepsis, and systemic inflammatory response syndrome are different clinical entities that probably represent a common immunopathological state, termed cytokine storm. These conditions may be clinically indistinguishable; all include massive inflammatory response, elevated serum cytokine levels, multi-organ involvement, haemophagocytic macrophages, and often death. Tissues of haematopoietic and lymphoid function are directly involved; other organs are secondarily damaged by circulating cytokines and chemokines. Haemophagocytic disorders are now increasingly diagnosed in the context of severe inflammatory reactions to viruses, malignancies and systemic connective tissue diseases. Many of these cases may reflect underlying genetic predispositions to HLH. The detection of gene defects has contributed considerably to our understanding of HLH, but the mechanisms leading to acquired HLH have yet to be fully determined.

Loss of 5-hydroxymethylcytosine is an epigenetic hallmark of melanoma.

DNA methylation at the 5 position of cytosine (5-mC) is a key epigenetic mark that is critical for various biological and pathological processes. 5-mC can be converted to 5-hydroxymethylcytosine (5-hmC) by the ten-eleven translocation (TET) family of DNA hydroxylases. Here, we report that "loss of 5-hmC" is an epigenetic hallmark of melanoma, with diagnostic and prognostic implications. Genome-wide mapping of 5-hmC reveals loss of the 5-hmC landscape in the melanoma epigenome. We show that downregulation of isocitrate dehydrogenase 2 (IDH2) and TET family enzymes is likely one of the mechanisms underlying 5-hmC loss in melanoma. Rebuilding the 5-hmC landscape in melanoma cells by reintroducing active TET2 or IDH2 suppresses melanoma growth and increases tumor-free survival in animal models. Thus, our study reveals a critical function of 5-hmC in melanoma development and directly links the IDH and TET activity-dependent epigenetic pathway to 5-hmC-mediated suppression of melanoma progression, suggesting a new strategy for epigenetic cancer therapy.