Peculiarities in the Diagnosis Approach of MDS /MPN-U Patients

The most recent WHO Classification of Tumors of Haematopoietic and Lymphoid Tissues describes a set of diseases framed as the MDS / MPN (myelodysplastic / chronic myeloproliferative syndromes). There are four subtypes comprised in this category: chronic myelomonocytic leukemia, juvenile myelomonocytic leukemia, atypical chronic myeloid leukemia and unclassifiable MDS / MPN. They combine both myelodysplastic and myeloproliferative features. Although the unclassifiable MDS/ MPN subtype specifically associates the myelodysplastic and myeloproliferative features, it does not meet the criteria defining the first 3 subtypes. The RARS-T subtype (refractory anemia with ringed sideroblasts associated with marked thrombocytosis) is included in the MDS / MPN-U as a temporary entity. There are two cases described in this article: one diagnosed with RARS-T and one with MDS / MPN-U. Both cases evolved towards acute myeloid leukemia.