BCL3 rearrangements in B-cell lymphoid neoplasms occur in two breakpoint clusters associated with different diseases.

The t(14;19)(q32;q13) often juxtaposes BCL3 with immunoglobulin heavy chain (IGH) resulting in overexpression of the gene. In contrast to other oncogenic translocations, BCL3 rearrangement (BCL3-R) has been associated with a broad spectrum of lymphoid neoplasms. Here we report an integrative whole-genome sequence, transcriptomic, and DNA methylation analysis of 13 lymphoid neoplasms with BCL3-R. The resolution of the breakpoints at single base-pair revealed that they occur in two clusters at 5' (n=9) and 3' (n=4) regions of BCL3 associated with two different biological and clinical entities. Both breakpoints were mediated by aberrant class switch recombination of the IGH locus. However, the 5' breakpoints (upstream) juxtaposed BCL3 next to an IGH enhancer leading to overexpression of the gene whereas the 3' breakpoints (downstream) positioned BCL3 outside the influence of the IGH and were not associated with its expression. Upstream BCL3-R tumors had unmutated IGHV, trisomy 12, and mutated genes frequently seen in chronic lymphocytic leukemia (CLL) but had an atypical CLL morphology, immunophenotype, DNA methylome, and expression profile that differ from conventional CLL. In contrast, downstream BCL3-R neoplasms were atypical splenic or nodal marginal zone lymphomas (MZL) with mutated IGHV, complex karyotypes and mutated genes typical of MZL. Two of the latter four tumors transformed to a large B-cell lymphoma. We designed a novel fluorescence in situ hybridization assay that recognizes the two different breakpoints and validated these findings in 17 independent tumors. Overall, upstream or downstream breakpoints of BCL3-R are mainly associated with two subtypes of lymphoid neoplasms with different (epi)genomic, expression, and clinicopathological features resembling atypical CLL and MZL, respectively.

CD34-Positive Blast Count and p53 Expression in Bone Marrow Biopsies of Patients with Low-Risk Myelodysplastic Syndromes: Potential Predictive Tools of Response to Erythropoietin Stimulating Agents.

INTRODUCTION: The first-line therapy for patients with low-risk myelodysplastic syndromes (MDSs) commonly consists of erythropoietin stimulating agents (ESAs), with a response rate ranging from 34 to 62%. For nonresponder patients, outside clinical trials, blood transfusions are the most frequent therapeutic option, with detrimental effect on the quality of life and with risks of iron-overload. Since no studies have been yet conducted on this topic, we investigated the potential predictive role of bone marrow (BM) histological evaluation in patients treated with ESAs. MATERIALS AND METHODS: We performed a morphological and immunohistochemical retrospective analysis of BM biopsies of 96 patients with low-risk MDSs subsequently treated with ESAs. RESULTS: In our series, substantial morphological overlap was found between responder and nonresponder patients. On the contrary, patients with a percentage of CD34-positive blasts >3% or with p53 protein expression <1% responded with a significantly higher frequency to ESAs. CONCLUSIONS: Our study reinforces the role of BM biopsy as diagnostic tool in MDSs, being also able to supply information related to response to ESAs and to its loss over time.

Odontogenic fibroma amyloid-variant: a typical case and brief considerations about mimickers.

The World Health Organization's (WHO) updated classification of head and neck tumors (2017) defined odontogenic fibroma as a rare neoplasm. In this report, we describe an unusual, typical and rare variant of a central odontogenic fibroma with diffuse amyloid-like protein stromal deposition, and discuss the differential diagnosis with other entities. Radiographically, this lesion presented as a well-defined radiolucency of the mandible, partially cystic. Histologically, the lesion showed a unique confluence of odontogenic epithelial rests in a moderately cellular connective tissue. Immunohistochemical staining highlighted a mixture of benign epithelial and Langerhans cells within connective tissue with diffuse amyloid-like stromal deposition. The importance of recognizing this variant of odontogenic fibroma is due to its benign prognosis and clinical course.

Clinical and molecular characteristics of lymphoplasmacytic lymphoma not associated with an IgM monoclonal protein: A multicentric study of the Rete Ematologica Lombarda (REL) network.

Lymphoplasmacytic lymphoma (LPL) is usually associated with a serum IgM paraprotein, corresponding to Waldenström's Macroglobulinemia (WM). Cases presenting with IgG or IgA, or without a monoclonal protein are extremely rare. We analyzed clinical characteristics, frontline treatment, and the outcome of 45 patients with non-IgM LPL, and compared them with a control group of WM patients. The median age was similar, with significantly higher prevalence of females in non-IgM LPL, than in WM patients (60% vs 39%, P = .016). Patients with non-IgM LPL more frequently presented with lymphadenopathies (53% vs 15%, P < .001), splenomegaly (22% vs 8%, P = .015) or extranodal involvement (20% vs 8%, P = .05). In non-IgM LPL a serum monoclonal protein and bone marrow infiltration were less common than in WM patients (69% and 84% of cases respectively, P < .001 for both comparisons). The MYD88 (L265P) mutation was found in 8/19 patients using allele-specific polymerase chain reaction. A CXCR4 mutation was found in 4/17 cases using Sanger. In 16 patients we performed targeted next-generation sequencing of genes MYD88, CXCR4, ARID1-A, KMT2D, NOTCH2, TP53, PRDM1, CD79B, TRAF3, MYBBP1A, TNFAIP3. Seven patients (44%) had a MYD88 mutation (S219C in one), four (25%) a CXCR4 mutation, three (19%) a KMT2D mutation, one (6%) a TP53 mutation and one (6%) a TRAF3 mutation. With a median follow-up of 55.7 months, 36 non-IgM LPL patients (80%) were treated. Non-IgM LPL patients received more frequently anthracycline-containing regimens, as compared with WM patients, who mainly received alkylating-based therapies. Five-year overall survival (OS) was 84%, similar to that of WM patients.

Cerebral Infectious Opportunistic Lesions in a Patient with Acute Myeloid Leukaemia: The Challenge of Diagnosis and Clinical Management.

Central nervous system (CNS) lesions, especially invasive fungal diseases (IFDs), in immunocompromised patients pose a great challenge in diagnosis and treatment. We report the case of a 48-year-old man with acute myeloid leukaemia and probable pulmonary aspergillosis, who developed hyposthenia of the left upper limb, after achieving leukaemia remission and while on voriconazole. Magnetic resonance imaging (MRI) showed oedematous CNS lesions with a haemorrhagic component in the right hemisphere with lepto-meningitis. After 2 weeks of antibiotics and amphotericin-B, brain biopsy revealed chronic inflammation with abscess and necrosis, while cultures were negative. Clinical recovery was attained, he was discharged on isavuconazole and allogeneic transplant was postponed, introducing azacitidine as a maintenance therapy. After initial improvement, MRI worsened; brain biopsy was repeated, showing similar histology; and 16S metagenomics sequencing analysis was positive (Veilonella, Pseudomonas). Despite 1 month of meropenem, MRI did not improve. The computer tomography and PET scan excluded extra-cranial infectious-inflammatory sites, and auto-immune genesis (sarcoidosis, histiocytosis, CNS vasculitis) was deemed unlikely due to the histological findings and unilateral lesions. We hypothesised possible IFD with peri-lesion inflammation and methyl-prednisolone was successfully introduced. Steroid tapering is ongoing and isavuconazole discontinuation is planned with close follow-up. In conclusion, the management of CNS complications in immunocompromised patients needs an interdisciplinary approach.

Efficacy and safety of cyclosporine A treatment in autoimmune cytopenias: the experience of two Italian reference centers.

Background: Immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA) show good responses to frontline steroids. About two-third of cases relapse and require second-line treatment, including rituximab, mainly effective in AIHA, and thrombopoietin-receptor agonists (TPO-RAs) in ITP, while the use of splenectomy progressively decreased due to concerns for infectious/thrombotic complications. For those failing second line, immunosuppressants may be considered. Objectives: The aim of this study was to evaluate the efficacy of cyclosporine treatment in patients with ITP and AIHA. Design: In this retrospective study, we evaluated the efficacy and safety of cyclosporine A (CyA) in ITP (N = 29) and AIHA (N = 10) patients followed at two reference centers in Milan, Italy. Methods: Responses were classified as partial [Hb > 10 or at least 2 g/dl increase from baseline, platelets (PLT) > 30 × 109/l with at least doubling from baseline] and complete (Hb > 12 g/dl or PLT > 100 × 109/l) and evaluated at 3, 6, and 12 months. Treatment emergent adverse events were also registered. Results: The median time from diagnosis to CyA was 35 months (3-293), and patients had required a median of 4 (1-8) previous therapy lines. Median duration of CyA was 28 (2-140) months and responses were achieved in 86% of ITP and 50% of AIHA subjects. Responders could reduce or discontinue concomitant treatment and resolved PLT fluctuations on TPO-RA. CyA was generally well tolerated, and only two serious infectious complications in elderly patients on concomitant steroids suggesting caution in this patient population. Conclusion: CyA may be advisable in ITP, which is not well controlled under TPO-RA, and in AIHA failing rituximab, particularly if ineligible in clinical trial.

Congenital aggressive variant of Langerhans cells histiocytosis with CD56+/E-Cadherin- phenotype.

In children < 2 years of age, cutaneous involvement is the most frequent presentation of Langerhans cell histiocytosis (LCH). Cutaneous LCH can be localized or associated with dissemination and organ dysfunction. The clinical course is variable, ranging from spontaneous regression to a fatal outcome. We describe a female newborn presenting with congenital cutaneous lesions who rapidly developed pulmonary infiltrates and multiple osteolytic lesions. Skin biopsy showed a dermal infiltrate of medium to large cells morphologically and phenotypically consistent with LCH. The clinical course was rapidly fatal in spite of chemotherapy. No strict correlation between morphology and prognosis has been documented in LCH, but, in our case, distinct morphological and immunohistochemical features (CD56 expression and no E-Cadherin expression) may have contributed to an aggressive clinical course.

Prognostic Impact of Immunohistochemical p53 Expression in Bone Marrow Biopsy in Higher Risk MDS: a Pilot Study.

BACKGROUND AND OBJECTIVES: Mutations of the TP53 gene have an unfavorable prognosis in Myelodysplastic Syndromes (MDS). The product of the TP53 gene is the p53 protein. Most of the TP53 mutations entail the accumulation of the protein in the nucleus of tumor cells. The immunohistochemical (IHC) staining for p53 can be a surrogate suggesting a mutational status and, if overexpressed, seems to be of prognostic value by itself. The best prognostic cut-off value of overexpression is controversial. The aim of this pilot study is to investigate the correct value from a homogenous group of patients with higher IPSS-R risk MDS. METHODS: In sixty consecutive patients diagnosed with MDS and categorized as "intermediate," "high" and "very high" IPSS-risk, the bone marrow biopsies performed at diagnosis were retrospectively re-examined for IHC p53 expression. The result of p53 expression was subsequently related to survival. RESULTS: A worse overall survival was observed both in patients whose IHC p53 expression was ≥5% and ≥ 10% compared to patients with a p53 expression below 5% (p= 0.0063) or 10% (p=0.0038) respectively. CONCLUSIONS: The ICH p53 expression in bone marrow biopsy in higher risk MDS was confirmed to have prognostic value. These results indicate more than 10% expression as the best cut off value.

A double-hit High-grade B-cell lymphoma with three-way translocation t(3;8;14)(q27;q24;q32) involving BCL6, MYC, and IGH.

We describe an High-grade B-cell lymphoma case, in which a complex translocation t(3;8;14) with effects on the genes BCL6, MYC, and IGH, was detected. This case could be the first double-hit lymphoma with a single chromosome rearrangement causing the double effect with three genes involved.

A Case of Blastic Plasmacytoid Dendritic Cell Neoplasm Extensively Studied by Flow Cytometry and Immunohistochemistry.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy with aggressive clinical course and poor prognosis. Diagnosis is based on detection of CD4+ CD56+, CD123high, TCL-1+, and blood dendritic cell antigen-2/CD303+ blasts, together with the absence of lineage specific antigens on tumour cells. In this report we present a case of BPDCN presenting with extramedullary and bone marrow involvement, extensively studied by flow cytometry and immunohistochemistry, who achieved complete remission after acute lymphoblastic leukemia like chemotherapy and allogeneic hematopoietic stem cell transplantation.

B-cell posttransplant lymphoproliferative disorders in heart and/or lungs recipients: clinical and molecular-histogenetic study of 17 cases from a single institution.

BACKGROUND: Posttransplantation lymphoproliferative disorders (PTLDs) are heterogeneous lymphoid proliferations representing a major complication of solid organ transplant. This study details the clinicopathological and molecular features of 17 B-cell PTLDs observed in a single center series of 988 heart and/or lung transplant recipients. METHODS: Cases were classified according to World Health Organization lymphoma classification and tested for Epstein-Barr Virus (EBV), clonality, histogenetic phenotypic (CD10, Bcl-6, MUM1, CD138), and genotypic (immunoglobulin and BCL-6 genes somatic hypermutation) markers. RESULTS: This series of 17 PTLDs included: two B-cell monoclonal polymorphic PTLDs and 15 B-cell monomorphic PTLDs (13 diffuse large B-cell lymphomas [DLBCL] and 2 Burkitt lymphomas [BL]). EBV was detected in 9/17 cases. A monoclonal immunoglobulin variable (IGV) genes rearrangement was documented in 17/17 cases; IGV somatic hypermutation was found in 88% of cases, indicating a prevalent origin from germinal center (GC)-experienced B cells. Using immunophenotypic markers, three histogenetic profiles were identified: a) CD10/bcl-6/MUM1/CD138, mimicking GC B-cells; b) CD10-/bcl-6+/MUM1+/CD138-, reminiscent of B-cells at the latest phases of GC reaction; and c) CD10-/bcl-6-/MUM1+/CD138+/-, consistent with preterminally differentiated B-cells. CONCLUSIONS: Correlation between morphology, histogenesis, and EBV status demonstrated a high degree of homogeneity in the two GC-related groups, mostly including EBV-negative cases with BL and DLBCL-centroblastic features; the third group, consisting of post GC EBV-positive cases, was histologically less homogeneous, as it included polymorphic PTLDs and DLBCL with immunoblastic and anaplastic features. The EBV-negative cases with GC histogenetic phenotype showed a slightly better outcome; however, such less aggressive prognostic trend was not confirmed by statistical analysis.

A case of compound mutations in the MYBPC3 gene associated with biventricular hypertrophy and neonatal death.

Hypertrophic cardiomyopathy (HCM) is a familial, genetically determined, primary cardiomyopathy caused by mutations in genes coding for proteins of the sarcomere, or, less frequently, genes involved in storage diseases. In pediatric settings, pure HCM has an estimated incidence of 4.7 per million children. The disease is often sub-clinical and goes unrecognized mainly because most patients with HCM have only mild symptoms, if any. However, sudden cardiac death, the most dramatic clinical occurrence and the primary concern for patients and physicians alike, may be the first manifestation of the disease. We describe a case of compound heterozygosity in the MYBPC3 gene (p.Glu258Lys and IVS25-1G>A) associated with biventricular hypertrophy, atrial enlargement and subsequent neonatal death 33 days postpartum. Other studies have reported compound and/or double heterozygosis in the same or different sarcomeric genes during childhood and adulthood, and neonatal presentations have also been described. Our observations show that the combination of a missense (p.Glu258Lys) and a splice-site mutation (IVS25-1G>A) profoundly affects the clinical course. In families in which parental mutations are known, preimplantation (where ethically and legally feasible) or prenatal genetic screening should be adopted because: (1) neonatal HCM in genetic heterozygosity is potentially lethal and (2) heart disease is the most common developmental malformation and the leading cause of neonatal mortality and morbidity.