MDS/MPN with ringed sideroblasts and thrombocytosis, and secondary or concurrent mastocytosis: case report and literature review

Myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN with RS-T), which exhibits both an increased number of marrow ring sideroblasts and thrombocytosis, is a rare disorder classified as one of the newly established forms of MDS/MPN in the WHO 2016 classification. Systemic mastocytosis (SM) is a heterogeneous group of neoplasms characterized by growth and accumulation of both cytologically and immunophenotypically abnormal mast cells in one or more body organ systems. SM can occur as a separate neoplasm but commonly is associated with other clonally related myeloid neoplasms. Herein, we present a 78-year-old female with a clinical history of fatigue, dyspnea, and a compression fracture of L5. Her peripheral blood, bone marrow aspirate, and biopsy laboratory workup show features of myelodysplasia with ring sideroblasts, thrombocytosis, and clusters of mast cells in the bone marrow biopsy. Pathogenic c-KIT, MPL, and SF3B1 genes are identified by the molecular study. We present this case to point out a rare combination of systemic mastocytosis and MDS/MPN with ring sideroblasts and thrombocytosis. It is not known if the best treatment should be focused on the systemic mastocytosis or the accompanying MDS/MPN.