Ring Sideroblasts and a Normal Karyotype in Bone Marrow of Patients Treated for Primary Malignancies and Developed Cytopenia.
Chi Young Ok, Yi Zhou, Ying Hu, L Jeffrey Medeiros, Sa Wang. University of Massachusetts, Worcester; UT MD Anderson Cancer Center, Houston, TX
Background: Therapy-related myeloid neoplasms (t-MN) often harbor cytogenetic abnormalities and carry a dismal prognosis. A small percentage of t-MN, however, have a normal karyotype and a low blast count. Assessment of such cases can be extremely challenging since dysplastic changes often become less reliable for a diagnosis of myelodysplastic syndromes (MDS) in patients undergoing various therapies. The presence of substantial number of ring sideroblasts (RS) often favors a diagnosis of t-MN. In this project, we assessed the clinical significance of RS in the therapy-related setting.
Design: We searched the pathology files of our hospital for cases with a suspicion or a confirmed diagnosis of t-MN. All cases in this study cohort had cytogenetic data. Each case was carefully reviewed in conjunction with laboratory data, subsequent bone marrow biopsy and clinical follow-up.
Results: We identified 845 patients with a diagnosis of t-MN entertained by the pathologists. 128 cases (15%) had a normal karyotype, of which, 45 were classified as acute myeloid leukemia (AML) and 83 MDS. 23 of 83 (28%) of the MDS cases contained ≥15% RS, <5% blasts and a normal karyotype. After reviewing treatment information and follow-up data, we confirmed 13 of these cases to be t-MDS. In 3 cases, proximity to cytotoxic therapy (<3 month) suggested that the MDS was not therapy-related. In the remaining 7 cases, RS and associated dyserythropoiesis disappeared in follow-up BM aspiration smears and biopsy sections, and cytopenia improved without intervention. Compared with t-MDS cases, the latter group demonstrated comparable cellularity, RS range and blast count. However, dysplasia was confined to erythroid lineage in all 7 cases while 46% of t-MDS cases demonstrated dysplasia in two or more lineages. With a median follow-up length of 10 months, 7/13 patients with t-MDS and RS died, and at least two died of MDS-related causes. In contrast, none of the 7 patients with RS and only dyserythropoiesis died of BM causes.
Conclusions: t-MN is a serious complication in patients who have received cytotoxic therapy. In cases with a normal karyotype, we conclude that the presence of RS is not necessarily indicative of t-MDS. In some cases, RS likely reflect impaired heme-synthesis related to the patient's underlying medical condition or therapeutic agents and these changes appear to be reversible.
Monday, February 28, 2011 1:00 PM
Poster Session II # 168, Monday Afternoon