An Unlikely Rapid Transformation of Myelodysplastic Syndrome to Acute Leukemia: A Case Report.

INTRODUCTION: Myelodysplastic syndrome is characterized by stem-cell-derived clonal myelopoiesis with an alteration in proliferation and differentiation. This condition carries a potential for transformation to acute leukemia, primarily in cases that are accompanied by high-risk features at diagnosis.

CASE PRESENTATION: A 68-year-old man with recently diagnosed myelodysplastic syndrome and Sweet syndrome (acute febrile neutrophilic dermatosis) presented to our Emergency Department with shortness of breath. During his hospital course, he developed signs and symptoms, predominantly consisting of respiratory difficulties, that were not typically characteristic of transformation to acute leukemia. Several days into his hospitalization, it was determined that the patient's underlying hematologic process seemed to have rapidly evolved into an acute myeloid leukemia, which accounted for the progression of symptoms. This patient ultimately opted for comfort measures only and died shortly thereafter.

DISCUSSION: Two important factors stood out as representing an atypical presentation. First, this patient lacked any of the high-risk features of myelodysplastic syndrome that typically portend transformation. In addition, his progression to acute leukemia in 28 days from the time of diagnosis was far more rapid than the 274-day median previously described in the literature. We theorize that the presence of Sweet syndrome may have served as a predisposing factor to transformation. This finding may offer benefit to physicians to potentially better predict this outcome and pursue more aggressive treatment measures earlier in the course of the disease in such a setting.