HJBR Mar/Apr 2022

50 MAR / APR 2022 I  HEALTHCARE JOURNAL OF BATON ROUGE DIALOGUE COLUMN ONCOLOGY An 81-year-old man presents to his pri- mary care physician for a routine well visit. He reports some mild fatigue; however, he is in his usual state of health. Routine complete blood count is only significant for macro- cytic anemia with a hemoglobin of 9.8 and mean corpuscular volume of 106. Subsequent workup, including copper, vitamin B-12 and folate levels are normal. Patient’s peripheral smear is reviewed and is noted to have mac- rocytosis and neutrophils with nuclear hypo- segmentation and chromatin clumping. The patient is referred to hematology for evalua- tion, where bone marrow examination con- firms a diagnosis of low-risk myelodysplas- tic syndrome. After shared decision-making, patient opts for supportive care. What is Myelodysplastic Syndrome (MDS)? Myelodysplastic Syndrome is defined as a group of clonal hematologic malignancies that arise from abnormal maturation of the hematopoietic stem cells. 1 The progeny of this abnormal maturation dominates in the bone marrow and contributes to ineffective hematopoiesis. Thus, resulting in clinical cy- topenia. MDS is noted to be closely related to acute myeloid leukemia (AML). However, one major difference is the blast count in MDS does not meet the AML threshold of greater than 20%. Classically, MDS is a condition that affects older individuals with a median age of clinical presentation of 70 years. MDS should be considered when an older individual is noted to have macrocytic anemia without other identifiable etiologies. What causes MDS? The clonality that defines MDS arises from mutations in the hematopoietic stem cell population. Genetic driver mutations are associated with greater than 90% of patients withMDS. These mutations are found in tran- scription factors, epigenetic regulators, and splice site regulators. Other patients have suspected associations with environmental exposures namely, radiation, tobacco, pet- rochemicals, or benzene. MDS can arise as a late consequence of chemotherapy treatment. Characteristically, MDS can occur five to sev- en years following treatment with alkylating MDS: When a Routine CBC Signals a Change