Review Question - QID 216586

This patient is presenting with confusion, slurred speech, dizziness, ataxia, an elevated leukocyte count > 50,000, and a positive BCR-ABL gene which is concerning for chronic myelogenous leukemia (CML). Acute blast crisis is a complication that can lead to hyperviscosity which is likely causing this patient’s symptoms.

Blast crisis is a life threatening complication of chronic myelogenous leukemia where there is an excess and rapid production of blasts where there are often > 50,000 cells many of which are blasts (often > 20%). These patients can be critically ill and are at high risk for infection given the lack of functional immune cells. The excess of blasts also can lead to sludging and hyperviscosity with end organ dysfunction leading to symptoms including headache, dizziness, visual changes, or even stroke. Acute blast crisis often requires leukapheresis to remove the excess cells and improve end organ perfusion.

Hehlman et al. note the management of blast crisis and that there is a high mortality associated with this condition and a myriad of chemotherapeutic regimens.

Incorrect Answers:
Answer 2: Arteriovenous malformations predispose patients to intraparenchymal hemorrhage which presents with altered mental status, focal neurologic deficits, and an intraparenchymal bleed on head CT. This is a more common cause of intraparenchymal bleeds in pediatric patients.

Answer 3: Dysproteinemias such as hyper IgM syndrome can lead to sludging and hyperviscosity and similar symptoms to a blast crisis with impaired end organ perfusion. However, it would be less likely in CML.

Answer 4: Plaque rupture could cause an acute ischemic stroke in eldelry patients with atherosclerosis; however, this patient’s more global symptoms without a clear set of focal neurologic deficits in the setting of CML make blast crisis a more likely diagnosis.

Answer 5: Polycythemia vera results in an increased production of red blood cells which can lead to a hyperviscosity syndrome and impaired end organ perfusion which can acutely be treated with phlebotomy and IV fluids. Note that in CML patients are often anemic.

Bullet Summary:
Blast crisis is a complication of chronic myelogenous leukemia and presents with an elevated blast level with signs of end organ dysfunction.