Clinical boundaries in adult cases of large B cell lymphoma with IRF4 rearrangement.

AIMS: Large B-cell lymphoma with IRF4 rearrangement (LBCL-IRF4) is a recently described entity included in the revised 4th edition of the WHO Classification of Haematolymphoid Tumours (2017). Here we highlight the difficulties in classification of those cases which arise in adult patients with unusual clinical features. RESULTS: We present three cases with morphological and immunohistochemical features consistent with large B-cell lymphoma arising in adult patients, which were found to have isolated IRF4 rearrangements on FISH analysis. Each patient presented with advanced-stage disease and had a history of immunosuppression; clinical features that are not typical of LBCL-IRF4 and which make the distinction from DLBCL, not otherwise specified (NOS) challenging. CONCLUSION: We propose that the clinical boundaries of LBCL-IRF4 arising in adult patients need further delineation to allow distinction from true cases of DLBCL, NOS.

TP53 Mutations Identified Using NGS Comprise the Overwhelming Majority of TP53 Disruptions in CLL: Results From a Multicentre Study.

Limited data exists to show the correlation of (tumour protein 53) TP53 mutation detected by Next generation sequencing (NGS) and the presence/absence of deletions of 17p13 detected by FISH. The study which is the largest series to date includes 2332 CLL patients referred for analysis of del(17p) by FISH and TP53 mutations by NGS before treatment. Using a 10% variant allele frequency (VAF) threshold, cases were segregated into high burden mutations (≥10%) and low burden mutations (<10%). TP53 aberrations (17p [del(17p)] and/or TP53 mutation) were detected in 320/2332 patients (13.7%). Using NGS analysis, 429 TP53 mutations were identified in 303 patients (13%). Of these 238 (79%) and 65 (21%) were cases with high burden and low burden mutations respectively. In our cohort, 2012 cases did not demonstrate a TP53 aberration (86.3%). A total of 159 cases showed TP53 mutations in the absence of del(17p) (49/159 with low burden TP53 mutations) and 144 cases had both TP53 mutation and del(17p) (16/144 with low burden mutations). Only 17/2332 (0.7%) cases demonstrated del(17p) with no TP53 mutation. Validated NGS protocols should be used in clinical decision making to avoid missing low-burden TP53 mutations and can detect the vast majority of TP53 aberrations.

Emergence of Bruton's tyrosine kinase-negative Hodgkin lymphoma during ibrutinib treatment of chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) is a chronic B-cell lympho-proliferative disorder in which lymphomatous transformations occur in 5%-15% of patients. Histologically these cases resemble diffuse large B-cell lymphoma, or Richter's transformation, in over 80% of cases. Rare cases of transformation to Hodgkin lymphoma (HL) have been reported in the literature with an estimated prevalence of 0.4%. We report a case of a 67-year-old female with CLL treated with the novel Bruton's tyrosine kinase (Btk) inhibitor, ibrutinib, who subsequently presented with intractable fevers. Bone marrow trephine, and lymph node biopsy revealed classical HL with negative immuno-histochemistry for Btk in HL cells, on a backdrop of CLL. The patient commenced treatment with Adriamycin, Vinblastine and Dacarbazine (AVD), which resulted in an excellent response. Hodgkin transformation of CLL is rare with a single retrospective study of 4121 CLL patients reporting only 18 cases. Btk expression in HL cells is recently recognised in classical HL; however, the majority of HLs are Btk negative. Given that Btk inhibitors have recently been shown to induce genomic instability in B cells, in the context of their widespread use, such emerging cases are increasingly relevant.

Molecular heterogeneity of familial myeloproliferative neoplasms revealed by analysis of the commonly acquired JAK2, CALR and MPL mutations.

The myeloproliferative neoplasms (MPN) are clonal, hematological malignancies that include polycythemia vera, essential thrombocythemia and primary myelofibrosis. While most cases of MPN are sporadic in nature, a familial pattern of inheritance is well recognised. The phenotype and status of the commonly acquired JAK2 V617F, CALR exon 9 and MPL W515L/K mutations in affected individuals from a consecutive series of ten familial MPN (FMPN) kindred are described. Affected individuals display the classical MPN phenotypes together with one kindred identified suggestive of hereditary thrombocytosis. In affected patients the JAK2 V617F mutation is the most commonly acquired followed by CALR exon nine mutations with no MPL W515L/K mutations detected. The JAK2 V617F and CALR exon 9 mutations appear to occur at approximately the same frequency in FMPN as in the sporadic forms of these diseases. The familial nature of MPN may often be overlooked and accordingly more common than previously considered. Characterisation of these FMPN kindred may allow for the investigation of molecular events that contribute to this inheritance.

EBMT risk score predicts outcome of allogeneic hematopoietic stem cell transplantation in patients who have failed a previous transplantation procedure.

Increasing numbers of allogeneic hematopoietic stem cell transplantation (allo-SCT) are being performed for patients who have failed a previous allogeneic or autologous SCT. We investigated whether the EBMT risk score could predict outcome after a subsequent allo-SCT. We analyzed prognostic factors in 124 consecutive patients who underwent a second transplantation using an allogeneic donor at our institution. Patients with either a first autologous (N = 64) or first allogeneic (N = 60) SCT were included. Age, disease stage, time interval from diagnosis to transplantation, donor type, and donor-recipient sex combination were used to establish a score from 0 to 7 points, from which 3 groups were identified. The 5-year survival probability decreased from 51.7% for risk scores 0-3 (low, n = 25), to 29.3% for risk score 4 (intermediate, n = 42), and only 10.4% for risk scores 5-7 (high, n = 57), P = .001. We propose that the EBMT risk score can identify patients most likely to benefit from a second transplantation.

Haematological emergencies managing hypercalcaemia in adults and children with haematological disorders.

Hypercalcaemia is a common metabolic complication of malignant disease often requiring emergency intervention. Although it is more frequently associated with solid tumours, malignancy-associated hypercalcaemia (MAH) is seen in a significant number of patients with blood diseases. Its association with myeloma and adult T-cell leukaemia/lymphoma is well recognized but the incidence of hypercalcaemia in other haematological neoplasms, affecting adults and children, is less clearly defined. Haematologists need to be familiar with the clinical manifestations of, the differential diagnosis to be considered and the most effective management strategies that are currently available for MAH. The key components of management of MAH include aggressive rehydration, specific therapy to inhibit bone resorption and, crucially, treatment of the underlying malignancy. Bisphosphonates have revolutionized the management of MAH over the last 20 years, however the elucidation of molecular pathways implicated in MAH is facilitating the development of more targeted approaches to treatment.

Large granular lymphocyte leukemia: natural history and response to treatment.

Large granular lymphocyte leukemia (T-LGL) is an indolent T lymphoproliferative disorder that was difficult to diagnose with certainty until clonality testing of the T cell receptor gene became routinely available. We studied the natural history and response to treatment in 25 consecutive patients with T-LGL diagnosed between 2004 and 2008 in which the diagnosis was confirmed by molecular analysis, to define an effective treatment algorithm. The median age at diagnosis was 61 years (range 27-78), with a male to female ratio of 1:1.8 and presenting features of fatigue (n = 13), recurrent infections (n = 9), and/or abnormal blood counts (n = 5). Thirteen patients with symptomatic disease were treated as follows: pentostatin (nine patients), cyclosporine (six patients), methotrexate (three patients), and alemtuzumab in two patients in whom pentostatin was ineffective. Pentostatin was the single most effective therapy, with a response rate of 75% and minimal toxicity. The overall survival (OS) and progression-free survival (PFS) 37 months from diagnosis were 80% and 52%, respectively. Treatment of T-LGL should be reserved for patients with symptomatic disease, but in this series, pentostatin treatment was less toxic and more effective than cyclosporine or methotrexate.

Candida albicans-associated necrotizing vasculitis producing life-threatening gastrointestinal hemorrhage.

Patients undergoing treatment of acute lymphoblastic leukemia are at risk for fungal infections including disseminated candidiasis. We describe a case of systemic Candida albicans infection associated with life-threatening gastrointestinal hemorrhage due to unusual necrotizing vasculitis involving the gastrointestinal tract. We explore the association between Candida and such vasculopathy.