LAUSR

Myelodysplastic syndrome (MDS) with isolated del(5q) [MDS del(5q)] is a World Health Organization (WHO)recognized MDS entity. It is characterized by an interstitial deletion on chromosome 5q occurring either in isolation or with one additional cytogenetic abnormality, other than monosomy 7 or del(7q). Its presentation includes anemia, usually macrocytic, normal to elevated platelet count and normal white blood count. Bone marrow (BM) is normocellular to mildly hypercellular, often with erythroid hypoplasia; the presence of non-lobated megakaryocytes is characteristic. MDS del(5q) is considered a “low-grade” MDS; however, transformation to acute myeloid leukemia does occur and is frequently associated with gain of a TP53 mutation. The occurrence of other mutations has not been extensively studied. A small proportion of MDS del(5q) shows concomitant JAK2 V617F mutation. Due to the limited data available, it is unclear whether JAK2 V617F affects the phenotypic manifestations and/or prognosis. To clarify this issue, we retrospectively reviewed the files of the Division of Hematopathology at New York Presbyterian/Weill Cornell Medicine (NY, USA). A total of 47 cases of MDS del(5q) were identified between 2001 and 2018. Material was reviewed to verify that the diagnoses met the criteria of the Revised 4th Edition of the WHO Classification. Six cases (12.7%) had the JAK2 V617F mutation. A summary of the main clinical and pathological data at diagnosis and information on