Lenalidomide: A double-edged sword for concomitant multiple myeloma and post-essential thrombocythemia myelofibrosis

A 69-year old Caucasian man presented at our Institution in 2011 for a thrombocytosis discovered in the past year (platelet count 600–650 × 109/L). His medical history included habitual smoking, and a transitory ischemic attack (TIA) that occurred six years before, prompting starting therapy with acetylsalicylic acid (ASA, ie, 100 mg/daily). Physical examination was unremarkable. At referral, blood tests confirmed mild thrombocytosis (platelet count 688 × 109/L) without any other hematologic abnormality: hemoglobin (Hb) was 14.3 g/dL and white blood cells (WBC) were 8.8 × 109/L with a normal differential count. Secondary causes of thrombocytosis were excluded, serum lactate dehydrogenase (LDH) level was increased (371 U/L, reference range 135–225 U/L).