Myeloid neoplasms in the setting of sickle cell disease: an intrinsic association with the underlying condition rather than a coincidence; report of 4 cases and review of the literature.

Myeloid neoplasms occasionally occur in patients with sickle cell disease, and the underlying connection between the two diseases is unclear. Herein, we retrospectively analyzed four cases of sickle cell disease patients who developed myeloid neoplasm. Age at time of diagnosis ranged from 27 to 59 years with a median of 35.5 years. Two patients were treated with hydroxyurea and the other two with supportive care alone, with one out of the four patients receiving additional treatment with hematopoietic stem cell transplant. Three patients presented with leukocytosis, and the remaining patient presented with pancytopenia. Two patients were diagnosed with myelodysplastic syndrome/myeloproliferative neoplasm, one with myelodysplastic syndrome, and the other with acute myeloid leukemia. All four cases demonstrated certain degrees of myelodysplasia and complex cytogenetic abnormalities with - 7/7q- and/or - 5/5q- or with 11q23 (KMT2A) rearrangement. This cytogenetic profile resembles that seen in therapy-related myeloid neoplasm, suggesting that myeloid neoplasm in the setting of sickle cell disease may represent a subcategory of the disease distinct from de novo myeloid neoplasm in general. Extensive literature review further demonstrates this similarity in cytogenetic profile, as well as in other associated pathologic features. Potential etiology includes therapy for sickle cell disease, disease-related immunomodulation, or disease-related chronic inflammation. We hypothesize that constant hematopoietic hyperplasia, stimulated by a hemolysis-induced cytokine storm, may increase the chance of somatic mutations/cytogenetic aberrations, resulting in transformation of myeloid precursors. This group of myeloid neoplasms seems to herald a dismal clinical outcome, with median survival <1 year, although the exact pathogenesis and biology of the disease remain to be investigated by large cohorts in future studies.

Genetic heterogeneity of diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma in adults. The disease exhibits a striking heterogeneity in gene expression profiles and clinical outcomes, but its genetic causes remain to be fully defined. Through whole genome and exome sequencing, we characterized the genetic diversity of DLBCL. In all, we sequenced 73 DLBCL primary tumors (34 with matched normal DNA). Separately, we sequenced the exomes of 21 DLBCL cell lines. We identified 322 DLBCL cancer genes that were recurrently mutated in primary DLBCLs. We identified recurrent mutations implicating a number of known and not previously identified genes and pathways in DLBCL including those related to chromatin modification (ARID1A and MEF2B), NF-κB (CARD11 and TNFAIP3), PI3 kinase (PIK3CD, PIK3R1, and MTOR), B-cell lineage (IRF8, POU2F2, and GNA13), and WNT signaling (WIF1). We also experimentally validated a mutation in PIK3CD, a gene not previously implicated in lymphomas. The patterns of mutation demonstrated a classic long tail distribution with substantial variation of mutated genes from patient to patient and also between published studies. Thus, our study reveals the tremendous genetic heterogeneity that underlies lymphomas and highlights the need for personalized medicine approaches to treating these patients.

Extranodal Castleman disease of the extremities: a case report and review of the literature.

Castleman disease is a rare lymphoproliferative disorder of unknown etiology that most commonly presents as a mediastinal nodal mass or, in the extranodal form of the disease, a mass located in the mediastinum or retroperitoneum. It is exceptionally uncommon for Castleman disease to present in the extremities. We report a rare case of extranodal Castleman disease presenting as a muscular forearm mass. We compare our case with the seven other reported cases in which Castleman disease presented as an isolated soft tissue mass in the extremities.

Lymph node infarction: role of underlying malignancy, tumour proliferation fraction and vascular compromise--a study of 35 cases and a comprehensive review of the literature.

AIMS: To determine the roles of the presence of malignancy, tumour proliferation fraction, vascular compromise and therapeutic and diagnostic manipulations in lymph node infarction (LNI). METHODS AND RESULTS: Thirty-five cases of LNI were identified over a 20-year period. Of the 35 patients, 31 (89%) had an underlying malignancy: 27 of the 31 (87%) were haematologic malignancies, the rest being metastatic carcinoma (two), melanoma, and seminoma. Of the four patients without evidence of malignancy, two were diagnosed with viral infection, one had LNI adjacent to a thrombosed pancreas graft, and one was lost to follow-up. Ki67 immunostaining in viable tumour demonstrated a range (5-60%) of proliferation fractions. A history of fine needle aspiration alone was present in seven of the 35 patients (20%), a history of chemotherapy alone in 11 (31%), and a history of both in two (5.7%). Factor VIII immunostaining highlighted thrombosed and recanalized vessels next to the infarction. CONCLUSIONS: Infarction of lymph nodes is associated with previous, concurrent or subsequent diagnosis of malignancy in the vast majority of cases. Chemotherapy or previous fine needle aspiration can precipitate infarction in some cases, but infarction may occur without such intervention, possibly because of an underlying subacute or chronic vascular compromise produced by vascular thrombosis.

Deep sequencing of the small RNA transcriptome of normal and malignant human B cells identifies hundreds of novel microRNAs.

A role for microRNA (miRNA) has been recognized in nearly every biologic system examined thus far. A complete delineation of their role must be preceded by the identification of all miRNAs present in any system. We elucidated the complete small RNA transcriptome of normal and malignant B cells through deep sequencing of 31 normal and malignant human B-cell samples that comprise the spectrum of B-cell differentiation and common malignant phenotypes. We identified the expression of 333 known miRNAs, which is more than twice the number previously recognized in any tissue type. We further identified the expression of 286 candidate novel miRNAs in normal and malignant B cells. These miRNAs were validated at a high rate (92%) using quantitative polymerase chain reaction, and we demonstrated their application in the distinction of clinically relevant subgroups of lymphoma. We further demonstrated that a novel miRNA cluster, previously annotated as a hypothetical gene LOC100130622, contains 6 novel miRNAs that regulate the transforming growth factor-ß pathway. Thus, our work suggests that more than a third of the miRNAs present in most cellular types are currently unknown and that these miRNAs may regulate important cellular functions.

SMAD4 is required for development of maximal endotoxin tolerance.

Initial exposure of monocytes/macrophages to LPS induces hyporesponsiveness to a second challenge with LPS, a phenomenon termed LPS tolerance. Molecular mechanisms responsible for endotoxin tolerance are not well defined. We and others have shown that IL-1R-associated kinase (IRAK)-M and SHIP-1 proteins, negative regulators of TLR4 signaling, increase in tolerized cells. TGF-beta1, an anti-inflammatory cytokine, is upregulated following LPS stimulation, mediating its effect through SMAD family proteins. Using a monocytic cell line, THP1, we show that LPS activates endogenous SMAD4, inducing its migration into the nucleus and increasing its expression. Secondary challenge with high dose LPS following initial low-dose LPS exposure does not increase IRAK-M or SHIP1 protein expression in small hairpin (sh)SMAD4 THP-1 cells compared with control shLUC THP1 cells. TNF-alpha concentrations in culture supernatants after second LPS challenge are higher in shSMAD4 THP-1 cells than shLUC THP1 cells, indicating failure to induce maximal tolerance in absence of SMAD4 signaling. Identical results are seen in primary murine macrophages and mouse embryonic fibroblasts, demonstrating the biological significance of our findings. TGF-beta1 treatment does not increase IRAK-M or SHIP1 protein expression in shSMAD4 THP-1 cells, whereas it does so in shLUC THP1 cells, indicating that TGF-beta1 regulates IRAK-M and SHIP1 expression through a SMAD4-dependent pathway. Knockdown of endogenous SHIP1 by shSHIP1 RNA decreases native and inducible IRAK-M protein expression and prevents development of endotoxin tolerance in THP1 cells. We conclude that in THP-1 cells and primary murine cells, SMAD4 signaling is required for maximal induction of endotoxin tolerance via modulation of SHIP1 and IRAK-M.

A role for E2F activities in determining the fate of Myc-induced lymphomagenesis.

The phenotypic heterogeneity that characterizes human cancers reflects the enormous genetic complexity of the oncogenic process. This complexity can also be seen in mouse models where it is frequently observed that in addition to the initiating genetic alteration, the resulting tumor harbors additional, somatically acquired mutations that affect the tumor phenotype. To investigate the role of genetic interactions in the development of tumors, we have made use of the Emu-myc model of pre-B and B cell lymphoma. Since various studies point to a functional interaction between Myc and the Rb/E2F pathway, we have investigated the role of E2F activities in the process of Myc-induced lymphomagenesis. Whereas the absence of E2F1 and E2F3 function has no impact on Myc-mediated tumor development, the absence of E2F2 substantially accelerates the time of tumor onset. Conversely, tumor development is delayed by the absence of E2F4. The enhanced early onset of tumors seen in the absence of E2F2 coincides with an expansion of immature B lineage cells that are likely to be the target for Myc oncogenesis. In contrast, the absence of E2F4 mutes the response of the lineage to Myc and there is no expansion of immature B lineage cells. We also find that distinct types of tumors emerge from the Emu-myc mice, distinguished by different patterns of gene expression, and that the relative proportions of these tumor types are affected by the absence of either E2F2 or E2F4. From these results, we conclude that there are several populations of tumors that arise from the Emu-myc model, reflecting distinct populations of cells that are susceptible to Myc-mediated oncogenesis and that the proportion of these cell populations is affected by the presence or absence of E2F activities.

Patterns of microRNA expression characterize stages of human B-cell differentiation.

Mature B-cell differentiation provides an important mechanism for the acquisition of adaptive immunity. Malignancies derived from mature B cells constitute the majority of leukemias and lymphomas. These malignancies often maintain the characteristics of the normal B cells that they are derived from, a feature that is frequently used in their diagnosis. The role of microRNAs in mature B cells is largely unknown. Through concomitant microRNA and mRNA profiling, we demonstrate a potential regulatory role for microRNAs at every stage of the mature B-cell differentiation process. In addition, we have experimentally identified a direct role for the microRNA regulation of key transcription factors in B-cell differentiation: LMO2 and PRDM1 (Blimp1). We also profiled the microRNA of B-cell tumors derived from diffuse large B-cell lymphoma, Burkitt lymphoma, and chronic lymphocytic leukemia. We found that, in contrast to many other malignancies, common B-cell malignancies do not down-regulate microRNA expression. Although these tumors could be distinguished from each other with use of microRNA expression, each tumor type maintained the expression of the lineage-specific microRNAs. Expression of these lineage-specific microRNAs could correctly predict the lineage of B-cell malignancies in more than 95% of the cases. Thus, our data demonstrate that microRNAs may be important in maintaining the mature B-cell phenotype in normal and malignant B cells.

Feasibility of low-dose interleukin-2 therapy following T-cell-depleted nonmyeloablative allogeneic hematopoietic stem cell transplantation from HLA-matched or -mismatched family member donors.

INTRODUCTION: High relapse rates and infections remain primary causes of failure in nonmyeloablative transplantation. Interleukin-2 (IL-2) may stimulate the immune system and improve outcomes. The primary objective of this pilot study was to evaluate the feasibility of administering IL-2 following a T-cell-depleted nonmyeloablative hematopoietic stem cell transplant. METHODS: Patients received T-cell-depleted nonmyeloablative transplant from a matched or mismatched related donor. Those with allogeneic engraftment,

Clinicopathologic findings in high-grade B-cell lymphomas with typical Burkitt morphologic features but lacking the MYC translocation.

In the World Health Organization classification, cases with classical Burkitt morphologic features and a very high proliferation fraction but without the MYC translocation are not clearly designated as a separate entity and are usually categorized as diffuse large B-cell lymphoma (DLBCL). We identified from our records 33 cases of highly aggressive mature B-cell neoplasms from 8 children and 25 adults with typical Burkitt cytomorphologic, histologic, and immunophenotypic (CD20+/CD10+ and surface immunoglobulin-positive) features. Rearrangement of MYC (MYC+) was present in only 18 of 33 cases, but the proliferation fraction was more than 90% in all MYC-cases (no MYC rearrangement). The immunophenotype of the lymphoma cells in the 2 groups was similar. Although children with MYC+ and MYC- neoplasms were treated with chemotherapy regimens appropriate for Burkitt lymphoma, adults with MYC- lymphomas received less aggressive therapy usually given for DLBCL. Survival analysis showed that adults in the MYC- group had an inferior outcome compared with adults with MYC+ disease. Provisional identification of MYC- lymphomas with typical Burkitt morphologic features as an entity separate from DLBCL will facilitate further studies and possible categorization as a separate entity.

Lineage Switch Between B-Lymphoblastic Leukemia and Acute Myeloid Leukemia Intermediated by "Occult" Myelodysplastic Neoplasm: Two Cases of Adult Patients With Evidence of Genomic Instability and Clonal Selection by Chemotherapy.

OBJECTIVES: Lineage switch occurs in rare leukemias, and the mechanism is unclear. We report two cases of B-lymphoblastic leukemia (B-ALL) relapsed as acute myeloid leukemia (AML). METHODS: Retrospective review of clinical and laboratory data. RESULTS: Complex cytogenetic abnormalities were detected in B-ALL for both cases with subclone heterogeneity. Postchemotherapy marrow biopsies showed trilineage hematopoiesis without detectable B-ALL. Cytogenetics in both showed stemline abnormalities. The cases were considered "occult" myelodysplastic syndrome (MDS) preceding B-ALL. The patients relapsed 6.5 and 9 months following induction, respectively. Case 1 relapsed as AML-M5 initially, was treated as such, and then relapsed again as B-ALL. Case 2 relapsed as AML-M6. Cytogenetics demonstrated persistent abnormalities. Both patients died soon after relapse. CONCLUSIONS: Lineage switch between B-ALL and AML could be intermediated by occult MDS. A pluripotent progenitor likely undergoes neoplastic transformation, resulting in a genomically unstable clone. This leads to a repertoire of heterogeneous subclones that may be selected by chemotherapy. Lineage switch heralds a dismal clinical outcome.

Posttransplant lymphoproliferative disorder after umbilical cord blood transplantation in children.

Reported are 7 cases of posttransplant lymphoproliferative disorder (PTLD) arising in children who received umbilical cord blood transplantation (UCBT). There were 4 females and 3 males with a median age of 3 years (range, 1-16 years). All 7 patients received UCBT, including 1 patient who received multiple units and 1 transplanted under nonmyeloablative condition. The time interval from UCBT to PTLD averaged 4 months (range, 2 weeks to 9 months). Patients typically presented with high-stage disease with visceral organ involvement. Histology of the PTLDs showed monomorphic morphology in 5 cases and polymorphic morphology in the remaining 2 cases. Bone marrow biopsies were performed in 3 cases and were negative for PTLD. Epstein-Barr virus (EBV) was detected in the PTLD in all 7 patients by in situ hybridization. Evidence of past EBV infection was found in the recipients, but the EBV genome was not detected in the donor cord blood samples, suggesting that donor cord blood was not the source of EBV infection. The origin of the PTLD was investigated in 5 cases. PTLD was of host origin in 2 patients who failed engraftment and of donor origin in the remaining 3 patients who had complete engraftment. Four of 5 patients with monomorphic PTLD failed to demonstrate significant responses to rituximab and/or reduction of immunosuppression and died within 1 month after diagnosis. The remaining 2 patients with polymorphic PTLD showed complete response to therapy. One patient was alive 35 months after transplant, and the other patient died of infection 6 months after transplant. It is concluded that PTLD arising after UCBT in children occurs early after transplant and represents a serious EBV-related complication. PTLD may be of donor or recipient origin depending on engraftment status. Both monomorphic and polymorphic histology may be seen, and monomorphic histology appears to predict an unfavorable prognosis.

Plasmacytic or lymphoplasmacytic infiltrate in lymph nodes: Diagnostic approach and differential considerations.

Plasmacytosis is a common finding in lymph node biopsies and can be seen in diverse circumstances ranging from reactive lymphadenopathy to malignant lymphoma. Familiarity with various histopathologic features of the different entities and awareness of their typical clinical and ancillary study findings are essential for an accurate diagnosis. In this review, we present common and representative nonneoplastic entities and lymphomas that have plasmacytic differentiation or associated plasmacytosis. We focus on the histological classification with an emphasis on the diagnostic approach and areas of diagnostic challenge.

Improved detection of diffuse large B-cell lymphoma by flow cytometric immunophenotyping-Effect of tissue disaggregation method.

BACKGROUND: Flow cytometric immunophenotyping (FCI) is recognized as a rapid, sensitive, and accurate method for diagnosis of B-cell lymphomas. We observed that FCI failed to identify the clonal B-cell population in several cases of large B-cell lymphoma (DLBCL) when tissue samples were prepared by a commercially available mechanical tissue disaggregation method. We tested a manual tissue disaggregation method and compared it with the mechanical method. METHODS: FCI findings from 51 cases of DLBCL processed with the mechanical tissue disaggregation method, 27 cases processed using the manual method, and 15 cases processed using a combination of both methods were compared. The histological and immunohistochemical findings in each case were reviewed. RESULTS: FCI detected a clonal B-cell population in 88.9% of cases processed by the manual tissue disaggregation method, 66.7% of cases processed by a combination of the manual and mechanical disaggregation methods, and in 62.7% of cases processed solely by the mechanical tissue disaggregation method (P < 0.01 Fisher exact). Manual processing yielded positive FCI results in 81.8% of the nodal tissue samples and 93.8% of the extra-nodal tissue samples, whereas mechanical disaggregation was particularly inefficient in preserving large lymphoma cells from extra-nodal tissue: 71.4% of the nodal and 56.8% of the extra-nodal tissue samples processed by the mechanical method showed clonal B-cells by flow cytometry (P < 0.006, Fisher exact). CONCLUSIONS: The diagnostic yield of FCI in DLBCL can be significantly improved by utilizing a manual disaggregation method, particularly in extra-nodal tissue samples. © 2015 International Clinical Cytometry Society.

Amiodarone-Induced Liver Injury and Cirrhosis.

We present a case report of an 80-year-old woman with volume overload thought initially to be secondary to heart failure, but determined to be amiodarone-induced acute and chronic liver injury leading to submassive necrosis and bridging fibrosis consistent with early cirrhosis. Her histopathology was uniquely absent of steatosis and phospholipidosis, which are commonly seen in AIC.

Blast phase in chronic myelogenous leukemia is skewed toward unusual blast types in patients treated with tyrosine kinase inhibitors: a comparative study of 67 cases.

OBJECTIVES: To compare the features of the blast phase of chronic myelogenous leukemia (CML) in patients treated with tyrosine kinase inhibitors (TKIs) with those in the pre-TKI era. METHODS: Sixty-seven patients with blast phase CML were identified in the Duke Pathology database from 1991 to 2011. The morphology and immunophenotype of blasts were evaluated, along with cytogenetic studies and associated findings in the peripheral blood and bone marrow. RESULTS: In the TKI era, the blasts were more frequently of a type other than the usual myeloid or lymphoid types when compared with the pre-TKI era. Blast phase in TKI-treated patients was associated with a higher peripheral WBC count and a lower blast percentage in the bone marrow. Of the 23 patients with cytogenetic studies during blast phase, additional cytogenetic changes more frequently occurred in patients with an unusual blast type, and some patients showed these changes months before the onset of blast phase. CONCLUSIONS: Blast phase CML in TKI- and non-TKI-treated patients differs in the morphology and immunophenotype of blasts, cytogenetic findings, and associated findings in the peripheral blood and bone marrow.

Burkitt lymphoma arising in organ transplant recipients: a clinicopathologic study of five cases.

We report five cases of Burkitt lymphoma arising in organ transplant recipients. There were four men and one woman with a mean age of 35 years. All were solid organ recipients with three renal, one liver, and one double lung transplantation. The time interval between organ transplantation and lymphoma averaged 4.5 years. Patients typically presented with high-stage disease with generalized lymphadenopathy and bone marrow involvement. Histology showed classic Burkitt lymphoma or atypical variant/Burkitt-like morphology. C-MYC rearrangement, including three cases with immunoglobulin heavy chain and two cases with lambda light chain, and Epstein-Barr virus were detected in all the cases. Additional chromosomal abnormalities were present in two of three cases and p53 mutation was found in one of three cases. Aberrant genotype and phenotype were frequently encountered, including minor monoclonal or oligoclonal T-cell populations and undetectable surface immunoglobulin light chain expression. Four patients received antilymphoma regimens, with combination chemotherapy (three patients) and/or Rituximab (three patients), in addition to reduction of immunosuppression. All four patients achieved complete remission. We conclude that posttransplant Burkitt lymphoma represents a characteristic clinicopathologic entity and occurs later after transplantation. Genotypic and phenotypic aberrations are often present. Rituximab may be an effective alternative to conventional combination chemotherapy in the treatment of a posttransplant Burkitt lymphoma.

Posttransplant lymphoproliferative disorder following nonmyeloablative allogeneic stem cell transplantation.

Posttransplantation lymphoproliferative disorder (PTLD) is a well-recognized complication of conventional bone marrow/stem cell and solid organ transplantation. However, not much is known about PTLD following the more recently introduced nonmyeloablative allogeneic stem cell transplantation (NMST). This study reports the findings from two cases of PTLD following NMST and compares them to the one previously reported case. The donor origin of the PTLD was determined using short tandem repeat analysis, and B- and T-cell clonalities were evaluated by polymerase chain reaction. Two cases of PTLD evolved in a total of 70 patients who have undergone NMST at our institution from 1999 to 2003. Both patients received conditioning with Fludarabine/Cytoxan/Campath 1H (alemtuzumab, anti-CD52 antibody) and T-cell-depleted donor cells with Campath-1H. Both PTLDs were EBV positive (by immunohistochemistry and in situ hybridization) with diffuse large B-cell lymphoma morphology. Our findings indicate the incidence of PTLD following NMST is 3% (2 of 70 patients from our institution and 1 of 30 from the previously reported case). All three PTLDs arose 6 to 7 months after NMST and were rapidly fatal. The pathology of the PTLD in all cases was donor origin, EBV positive, diffuse large B-cell lymphoma.