This page is dedicated to organizing various examples of standardized exam questions whose answer is polycythemia vera. While this may seem a odd practice, it is useful to see multiple examples of how polycythemia vera will be characterized on standardized exams (namely the boards and the shelf exams). This page is not meant to be used as a traditional question bank (as all of the answers will be the same), however seeing the classic “test” characterization for a disease is quite valuable.
KEY CHARACTERISTICS OF THIS CONDITION (ON EXAMS)
When it comes to standardized exams, each topic has its own “code” marked by key buzzwords, lab findings, clues, etc. If you are well versed in this code you will be able to more quickly identify the condition that is being discussed, and get the right answer on the exam you are taking. Below is the “code” for polycythemia vera.
- Itching during/after hot shower or bath: this is a very specific detail that pretty much gives away the diagnosis for this condition.
- Elevated hemoglobin/hematocrit can be present on a CBC
- Elevated platelets is also possible.
- Elevated WBCs is also possible
Question # 1
A 50 year old man comes to the clinic because he has been experiencing frequent itching, especially after taking a bath. His only other symptoms are a headache and dizziness. He denies any fever or weight loss. He explains that he has not seen a physician in the past decade, and he does not take any medications. His temperature is 98.4°F, blood pressure is 145/80 mm Hg, pulse is 74/min, an d respirations are 15/min. His BMI is 32 kg/m². His face appears to be ruddy with a cyanotic appearance. His spleen is palpable 3 cm below the left lower ribs, however the rest of his exam is unremarkable. Lab results are as follows:
- Hemoglobin: 22.0 g/dL**
- Platelets: 530,000/mm³
- Leukocytes: 15,000/mm³
What is the possible diagnosis in this patient?
Explanation # 1
Itching after taking a bath + increased hemoglobin = polycythemia vera
Question # 2
Explanation # 2
TESTABLE FACTS ABOUT THIS TOPIC (BEYOND ITS IDENTIFICATION)
Many questions on standardized exams go beyond simply recognizing the underlying topic. Often there are specific testable facts regarding some aspect of the topic’s pathophysiology/management/clinical implications that are commonly asked. Some of these are listed below:
- What causes it: most all patients with this condition have a V617F mutation involve the JAK2 gene.
- Consequence of mutation: Renders hematopeoiteic cells more sensitive to growth factors such as erythropoietin and thrombopoietin.
- Diagnosis: confirming low levels of erythropoietin and bone marrow aspiration cytogenetic studies showing a JAK2 mutation.
- Treatment: serial phlebotomy (as needed) to keep the hematocrit < 45%
Page Updated: 02.19.2017