Is it chronic idiopathic myelofibrosis, myelofibrosis with myeloid metaplasia, chronic megakaryocytic–granulocytic myelosis, or chronic megakaryocytic leukemia? Further thoughts on the nosology of the clonal myeloid disorders

Case report: A case of effective treatment of primary myelofibrosis with nodular panniculitis using ruxolitinib combined with corticosteroids

We report the case of a 54-year-old healthy Han Chinese male presenting with fever, pallor, erythematous subcutaneous nodules on the limbs, and significant anemia as indicated by routine blood tests, with no response to antimicrobial therapy. Initial skin biopsy was inconclusive. The erythematous subcutaneous nodules on the limbs rapidly progressed to widespread subcutaneous nodules across the body, with worsening anemia. Bone marrow biopsy revealed multifocal fibroblastic proliferation with focal fibrosis, classified as MF-2, and positive for the JAK2V617F mutation alongside SRSF2 positivity. Whole-body PET-CT scans did not reveal any lymph nodes or suspect lesions with high SUV uptake. A subsequent skin biopsy identified the condition as nodular panniculitis (NP), leading to a final diagnosis of primary myelofibrosis(PMF)with NP. The patient initially received treatment with oral ruxolitinib and prednisone acetate, resulting in normalization of body temperature, resolution of erythematous nodules, and normalization of blood parameters.

Myeloid Sarcoma with Megakaryoblastic Differentiation Arising in the Conjunctiva

An 87-year-old woman not known to have either a lymphoma or leukemia developed a left multinodular, fish-flesh superior epibulbar and forniceal mass. A biopsy disclosed a blastic tumor with scattered multinucleated immature megakaryoblasts. Immunophenotyping of bone marrow cells revealed strong positivity for CD7, CD31, CD43, CD45, CD61, and CD117; CD71, myeloperoxidase, and lysozyme were also positive in scattered cells. Forty percent of the neoplastic cells were Ki-67 positive. Cytogenetic studies indicated a trisomy 8 (associated with worse prognosis) and a t(12; 17) translocation. Desmin, smooth muscle actin, pancytokeratin, CAM 5.2, adipophilin, tryptase, S100, SOX10, MART1, and E-cadherin were negative, ruling out a nonhematopoietic tumor. The conjunctival lesion was diagnosed as a myeloid sarcoma with megakaryoblastic differentiation, a rare variant. It probably arose from a myelodysplastic syndrome. This is the first case of its type to develop in the conjunctiva.

Primary myelofibrosis (PMF), post polycythemia vera myelofibrosis (post-PV MF), post essential thrombocythemia myelofibrosis (post-ET MF), blast phase PMF (PMF-BP): Consensus on terminology by the international working group for myelofibrosis research and treatment (IWG-MRT)

The International Working Group for Myelofibrosis Research and Treatment (IWG-MRT) is comprised of hematologists, hematopathologists, and laboratory scientists and its main goal is to provide a forum for scientific exchange and collaboration. During its first general meeting in April 2006, the IWG-MRT established uniform treatment response criteria for chronic idiopathic myelofibrosis (CIMF); also known as agnogenic myeloid metaplasia (AMM), myelofibrosis with myeloid metaplasia (MMM), and many other names in the hematologic literature. This document summarizes the proceedings from the second meeting of the IWG-MRT, in November 2006, where the group discussed and agreed to standardize the nomenclature referring to CIMF: (i) the term primary myelofibrosis (PMF) was chosen over several other designations including CIMF, AMM, and MMM, (ii) myelofibrosis that develops in the setting of either polycythemia vera (PV) or essential thrombocythemia (ET) will be referred to as post-PV MF and post-ET MF, respectively, and (iii) "leukemic" transformation will be recognized as blast phase disease (PMF-BP, post-PV/ET MF in blast phase).

The genetic basis of myeloproliferative disorders

For many decades, myeloproliferative disorders (MPD) were largely neglected orphan diseases. The conceptual work of William Dameshek in 1951 provided the basis for understanding MPD as a continuum of related syndromes, possibly with a common pathogenetic cause. Recognition of the clonal origin of peripheral blood cells in MPD in 1976 and the ability to grow erythroid colonies in vitro in the absence of added growth factors in 1974 initiated the search for genetic alterations that might be responsible for myeloproliferation. Mutations in the genes for the erythropoietin receptor, thrombopoietin and the von Hippel-Lindau protein were found to cause familial syndromes resembling MPD, but despite their phenotypic similarities, none of these mutations were later found in patients with the sporadic form of MPD. The discovery of activating mutations in the Janus kinase 2 (JAK2) in most patients with MPD has fully transformed and energized the MPD field. Sensitive assays for detecting the JAK2-V617F mutation have become an essential part of the diagnostic work-up, and JAK2 now constitutes a prime target for developing specific inhibitors for the treatment of patients with MPD. Despite this progress, many questions remain unsolved, including how a single JAK2 mutation causes three different MPD phenotypes, what other genes might be involved in the pathogenesis, and what are the factors determining the progression to acute leukemia.