A 56 year-old man is brought to the emergency room by his family out of concern for a change in his mental status. The patient is not able to give a coherent history. His wife reports that he was previously healthy with the exception of a history of hypertension and hyperlipidemia. He started to feel tired over the previous 5 days, and earlier today was slurring his words and experiencing moments of disorientation. He had an appendectomy in the past. There is no family history of hematological disorders. He is taking hydrochlorothiazide and a statin. He denies any allergies to medications. He has never smoked and drinks one to two glasses of wine per week. He works as an accountant. The emergency room physician ordered a compete blood count (CBC), which showed a white cell count 11 x 109/L , Hb 8.1 g/dL and a platelet count 17 x 109/L. They accessed the patient’s old medical records and were able to determine that his CBC was normal just 3 months ago. They are concerned the patient has a serious hematological condition and they ask you to see him in consultation.