Case Presentation: A 46 year-old man presents with one week of intermittent headaches. The pain started in his neck and radiated to the eyes. There was associated nausea and vomiting. On the day of admission, he experienced visual hallucinations prompting him to seek medical care.
Further history revealed he was diagnosed with CML last year and had a blast crisis 3 months ago treated with induction chemotherapy, leukopharesis, and one round of intrathecal methotrexate due to concern of leukemic retinopathy. Cerebral spinal fluid (CSF) returned without blasts at that time. Bone marrow biopsy at 30 days after chemotherapy induction did not reveal any blasts and patient was continued on imatinib maintenance therapy.
On exam, the patient was afebrile with normal vital signs. Kernig, Brudzinski, and jolt testing were negative. He was alert and oriented with normal cognition and an otherwise normal exam.
No acute intracranial abnormality was noted on CT of the head. CBC returned with an elevated leukocyte count of 14,000/uL. The following day the patient developed diploplia and peripheral smear revealed 57% blasts. Cerebral spinal fluid (CSF) studies revealed leukocyte level of 1600/uL and 99% blasts confirming diagnosis of central nervous system (CNS) blast crisis.
Discussion: CNS blast crisis is a rare diagnosis but important to keep on the differential for any patient with CML who presents with a headache. Furthermore it is important to realize that imatinib has poor CSF penetration compared to second-generation tyrosine kinase inhibitor. This patient was treated with reinduction chemotherapy with cytarabine, etoposide, mitoxantrone, intrathecal methrotexate, and dasatinib. Despite treatment, a CNS blast crisis carries a poor prognosis with 88% mortality at 1 year.
Confounding this case was the fact that imatinib carries high rates of adverse side effects that mimic the common symptoms associated with CNS blast crisis: up to 38% of patients on imatinib experience headaches, up to 73% have nausea, and up 11% experience vision changes. Thus, it is important to have a low threshold to perform lumbar puncture as well as peripheral smear since CNS blast crises usually occur concurrently with systemic relapse. Per a review of available case reports, one cannot rely on meningeal signs to help point towards CNS blast crisis. The main presenting symptoms are headache, vomiting, and visual changes.
Conclusions: Hospitalists participate in the co-management of oncology patients on a more frequent basis. This case highlights the complications of cancer that hospitalists may be asked to diagnose in conjunction with consulting sub-specialists.