A 57-year-old man presents to the emergency department with several days of malaise, weakness, and night sweats. Today, he experienced a headache with blurry vision, thus prompting his presentation. The patient has a history of diabetes and is followed closely by an endocrinologist. Otherwise, he has lost 10 pounds over the past month. His temperature is 100°F (37.8°C), blood pressure is 122/90 mmHg, pulse is 84/min, respirations are 16/min, and oxygen saturation is 99% on room air. Physical exam is notable for a thin man but is otherwise unremarkable. His visual acuity is 20/100 in both eyes, though he says that he normally has 20/20 vision. His gait is mildly ataxic as well, but his neurological exam is otherwise nonfocal. Laboratory studies are ordered as seen below.

Hemoglobin: 10 g/dL
Hematocrit: 31%
Leukocyte count: 57,500/mm^3 with 35% blasts
Platelet count: 109,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.1 Eq/L
HCO3-: 22 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.1 mg/dL
Calcium: 10.0 mEq/L

Which of the following is the most likely diagnosis?
Acute lymphoblastic leukemia
Chronic lymphocytic leukemia
Multiple myeloma
Chronic myelogenous leukemia
Chronic myelogenous leukemia
This patient is presenting with symptoms of malignancy (malaise, weakness, and night sweats) and has a white blood cell count > 50,000/mm^3 in the setting of > 20% blasts, which are concerning for chronic myelogenous leukemia (CML). Given the blurry vision and ataxia in the setting of increased blasts, this patient may be suffering from a hyperviscosity syndrome secondary to a blast crisis, which can be seen in CML.

CML is a neoplastic proliferation of myeloid stem cells. Patients are often asymptomatic and may present with a white blood cell count > 50,000/mm^3. There are many different presentations. The chronic phase presents with < 10% blasts and is often asymptomatic. The accelerated phase has increased blasts, and patients present with fatigue, weight loss, malaise, night sweats, abdominal pain, and hepatosplenomegaly. Finally, the blast phase presents similar to the accelerated phase but with more severe symptoms. The blast phase may evolve into a blast crisis (> 20% blasts) which could cause a hyperviscosity syndrome. Hypervicosity syndrome may require IV fluids and leukapheresis. The most common translocation in CML is the 9;22 translocation which forms the BCR:ABL gene product.

Jain et al. review CML. They note the outcomes in patients in the blast phase in CML and how there are more poor outcomes associated with this phase. They recommend paying close attention and obtaining a CBC with a differential to determine the percent blasts.

Incorrect Answers:
Answer A: Acute lymphoblastic leukemia is more common in pediatric patients and presents with pancytopenia, fatigue, recurrent infections (from leukopenia), and bleeding (from thrombocytopenia). Other findings include systemic symptoms, malaise, fever, bone pain, lymphadenopathy, splenomegaly, and hepatomegaly.

Answer B: Acute myelogenous leukemia is a malignancy of myeloblasts and presents in the elderly. Patients will present with fatigue, malaise, weight loss, anorexia, fever, leukocytosis, anemia (causing fatigue), thrombocytopenia (causing bleeding), and neutropenia (leading to life-threatening infections). Auer rods can be seen on peripheral smear.

Answer C: Chronic lymphocytic leukemia is a monoclonal proliferation of incompetent mature B cells that occurs in elderly men and is the most common form of leukemia in the west. Patients are often asymptomatic and may have a white blood cell count > 50,000/mm^3. When symptomatic, patients may experience chills, weight loss, and weakness (note these symptoms are nonspecific). Peripheral smear will show smudge cells.

Answer E: Multiple myeloma is common in the elderly and presents with CRAB: hyperCalcemia, Renal insufficiency, Anemia, and lytic Bone lesions/Back pain. The diagnosis is supported with protein electrophoresis and confirmed when biopsy demonstrates increased plasma cells.

Bullet Summary:
Chronic myelogenous leukemia presents with increased white blood cells which may be >50,000/mm^3 (possibly with elevated blasts).