RT Journal Article
SR Electronic
T1 Essential thrombocythaemia with mutation in <em>MPL</em>: clinicopathological correlation and comparison with <em>JAK</em>2V617F-mutated and <em>CALR-</em>mutated genotypes
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 975
OP 980
DO 10.1136/jclinpath-2018-205227
VO 71
IS 11
A1 Alberto Alvarez-Larran
A1 Daniel Martínez
A1 Leonor Arenillas
A1 Ariadna Rubio
A1 Eduardo Arellano-Rodrigo
A1 Juan Carlos Hernández Boluda
A1 Natalia Papaleo
A1 Gonzalo Caballero
A1 Clara Martínez
A1 Francisca Ferrer-Marín
A1 María Isabel Mata
A1 Manuel Pérez-Encinas
A1 María Antonia Durán
A1 José María Alonso
A1 Gonzalo Carreño-Tarragona
A1 Juan Manuel Alonso
A1 Soledad Noya
A1 Elena Magro
A1 Raúl Pérez
A1 Mónica López-Guerra
A1 Irene Pastor-Galán
A1 Francisco Cervantes
A1 Carlos Besses
A1 Luis Colomo
A1 María Rozman
YR 2018
UL http://jcp.bmj.com/content/71/11/975.abstract
AB Aim To characterise the clinical and histological features of MPL-mutated essential thrombocythaemia (ET).Patients and methods Bone marrow biopsies of 175 patients with ET were centrally reviewed according to the 2016 WHO classification, including 42 cases with MPL mutation, 98 JAK2V617F-mutated and 35 CALR-mutated. Clinical and histological features were compared among the three genotypes included in the current 2016 WHO classification and among the different types of MPL mutations.Results Patients with MPL-mutated ET were significantly older than those with the other genotypes. Haematological values at diagnosis were similar among MPL-mutated and CALR-mutated ET, with both genotypes showing higher platelet counts and lower haemoglobin values than ET with JAK2V617F genotype. In the bone marrow, the median number of megakaryocytes was higher in MPL and CALR than in JAK2V617F genotype (16, 19 and 14 megakaryocytes per ×20 power field, respectively, p=0.004). Histological features of prefibrotic myelofibrosis were rarely observed in MPL genotype, whereas sinusoidal hyperplasia, dense clusters of megakaryocytes and reticulin fibrosis were more frequent in CALR-mutated ET, with 11% of such cases fulfilling WHO 2016 histological criteria of prefibrotic myelofibrosis. With a median follow-up of 3.5 years, no significant differences were seen among genotypes regarding survival, vascular complications or myelofibrotic transformation. There were no significant differences in the clinical data or in the histological characteristics depending on the type of MPL mutation.Conclusion MPL and CALR ET genotypes share clinical and histological characteristics. In contrast to CALR genotype, features of prefibrotic myelofibrosis are uncommon in MPL-mutated ET.