case_images: PMC7322597_01
case_images: (a) Bone marrow biopsy demonstrating megakaryocyte clustering with nuclear hypolobation and bulbous forms; (b) next-generation sequence analysis (Sequence Pilot, JSI Medical Systems, Ettenheim, Germany) identifying MPL p.W515S (c.1544G > C).
case_images: CRIHEM2020-8375986.001.jpg
case_images: PMC7322597_01_CRIHEM2020-8375986.001.jpg
case_images: fig1
case_images: Bone marrow biopsy was hypercellular with increased numbers of megakaryocytes showing paratrabecular clustering and nuclear hypolobation as well as bulbous forms (Figure 1(a)); granulopoiesis and erythropoiesis looked normal with World Health Organization grade 1 reticulin fibrosis seen that are all features in keeping with a diagnosis of prefibrotic myelofibrosis. Karyotypic analysis failed on the bone marrow aspirate; however, a next-generation sequencing approach identified p.(Trp515Ser), c.1544G > C mutation (NM_005373.2), usually referred to as MPL W515S, at an allele frequency of 35% in the patient's peripheral blood (Figure 1(b)).