Citations

In routine practice, the World Health Organization classification of systemic mastocytosis (SM) is also the de facto prognostic system; a core value is distinguishing indolent (ISM) from advanced SM (includes aggressive SM [ASM], SM with associated hematological neoplasm [SM‐AHN] and mast cell leukemia [MCL]). We sequenced 27 genes in 150 SM patients to identify mutations that could be integrated into a clinical‐molecular prognostic model for survival. Forty four patients (29%) had ISM, 25 (17%) ASM, 80 (53%) SM‐AHN and 1 (0.7%) MCL; overall KITD816V prevalence was 75%. In 87 patients, 148 non‐KIT mutations were detected; the most frequently mutated genes were TET2 (29%), ASXL1 (17%), and CBL (11%), with significantly higher mutation frequency in SM‐AHN > ASM > ISM (P < 0.0001). In advanced SM, ASXL1 and RUNX1 mutations were associated with inferior survival. In multivariate analysis, age > 60 years (HR = 2.4), hemoglobin < 10 g/dL or transfusion‐dependence (HR = 1.7), platelet count < 150 × 109/L (HR = 3.2), serum albumin < 3.5 g/dL (HR = 2.6), and ASXL1 mutation (HR = 2.3) were associated with inferior survival. A mutation‐augmented prognostic scoring system (MAPSS) based on these parameters stratified advanced SM patients into high‐, intermediate‐, and low‐risk groups with median survival of 5, 21 and 86 months, respectively (P < 0.0001). These data should optimize risk‐stratification and treatment selection for advanced SM patients. Am. J. Hematol. 91:888–893, 2016. © 2016 Wiley Periodicals, Inc.

We report a case of a 58-year-old woman who presented with a 1-month course of progressive lower and upper extremity weakness in addition to binocular diplopia. Diagnostic lumbar puncture revealed atypical lymphoid cells with 28% blasts. Immunophenotype was consistent with B cell acute lymphoblastic leukaemia (B-ALL). Further work up showed no systemic involvement but extensive thoracolumbar-sacral leptomeningeal disease. The patient was treated with several courses of intrathecal and systemic chemotherapy followed by craniospinal irradiation for consolidation. There was initial steady improvement in neurological symptoms and leptomeningeal disease, the latter being ascertained through radiological studies and cerebrospinal fluid examination. After 10 months of response, the patient relapsed with central nervous system (CNS) and systemic disease. B-ALL is a rare precursor lymphoid neoplasm that generally presents with systemic disease. While CNS involvement is not uncommon, isolated involvement of this compartment without systemic disease is exceedingly rare.

About 85% of patients with essential thrombocythemia (ET) harbor one of three driver mutations: JAK2, calreticulin (CALR), and MPL; the remaining ( ∼15%) are wild type for all three mutations and are referred to as being “triple negative.” Furthermore, CALR mutations in ET are structurally classified as type 1/type 1‐like or type 2/type 2‐like variants. The objective of the current study was to examine the impact of CALR mutation variant stratified driver mutational status on overall (OS), myelofibrosis‐free (MFFS), thrombosis‐free, and leukemia‐free survival (LFS) in ET; 495 patients (median age 58 years; 61% females) with ET were fully annotated for the their driver mutational status: 321 (65%) harbored JAK2, 109 (22%) CALR, and 12 (2%) MPL mutations and 11% were triple‐negative. Among the 109 CALR‐mutated cases, 52% were classified as type 1/type 1‐like and 48% as type 2/type 2‐like. In univariate analysis, triple‐negative patients displayed the best and MPL mutated the worst OS (P = 0.007); however, the difference in OS was no longer apparent on multivariable analysis that included age and sex as covariates (P = 0.5). LFS was also similar among the different mutational groups (P = 0.6) whereas MFFS was significantly shorter in MPL‐mutated patients on both univariate and multivariable analyses (age‐adjusted P = 0.02; HR 7.9, 95% CI 2.0–31.5). Also in multivariable analysis that included thrombosis history, age, and cardiovascular risk factors, the presence of JAK2 or MPL mutations was independently associated with higher risk of thrombosis (P = 0.02; HR 1.9, 95% CI 1.1–3.4). In conclusion, driver mutational status in ET does not appear to influence overall or LFS, even after CALR variant stratification. However, the presence of MPL mutations might be associated with a higher risk of fibrotic transformation and the presence of JAK2/MPL mutations with higher risk of thrombosis. Am. J. Hematol. 91:503–506, 2016. © 2016 Wiley Periodicals, Inc.