ABIM & Internal Medicine Shelf Exam Review Question of the Week: 54-year-old female with fatigue, easy bruising, and recurrent infections
As we begin #HemeWeek in our preparation of the ABIM and Internal Medicine Shelf exam review, here is a question directly out of the Knowmedge QVault. Give it your best shot and then see below for the answer.
54-year-old female presents to the clinic for fatigue, easy bruising, and recurrent infections. She was treated for breast cancer a few years ago and is currently in remission. She undergoes lab work that shows a white blood cell count of 49,000/μl that are not mature in nature. These cells also have azurophilic needle-shaped crystals in the cytoplasm of these cells. She is referred to oncology and undergoes a bone marrow aspirate. The bone marrow aspirate shows that she has a hypercellular bone marrow with 25% blast cells present. Which of the following is true of this patient’s disease?
A. Best treatment is seven days of cytosine arabinoside (ara-C) and three days of daunorubicin B. It has a poor prognosis C. Associated with t(9,22) chromosomal translocation D. Treatment is stem cell transplant E. Treatment includes all trans-retinoic acid (ATRA) and daunorubicin
ABIM Exam Practice Question Explanation
Based on her symptoms and laboratory findings, this patient likely has acute promyelogenous leukemia (aPML), also known as the M3 subtype of acute myelogenous leukemia (AML). Patients with aPML lose the ability to differentiate their myeloid precursor lines, but they retain the ability to replicate these cells. The replication of immature blast cells causes blasts to be present in the peripheral blood. These blasts also infiltrate the bone marrow, which leads to a hypercellular bone marrow. Diagnosis is confirmed when there is greater than 20% blast cells on bone marrow aspirate. Another clue that this patient has aPML is the presence of Auer rods or the intracytoplasmic needle crystals that were described in the vignette.
Now let’s go through the choices:
● Choice A (7 days of cytosine arabinoside (ara-C) and 3 days of daunorubicin) would be the treatment if the patient had non-M3 AML.
● Choice B (Poor prognosis) is an incorrect statement since aPML has the best overall prognosis of all the types of AML. The remission rate with aPML is close to 80% with cure rates around 70%.
● Choice C (t(9,22) chromosomal translocation) is incorrect since t(9,22) is seen with chronic myelogenous leukemia (CML) and acute lymphoblastic leukemia (ALL), not aPML. Of note, t(9,22) is a good prognostic factor for CML patients but is a poor prognostic factor for ALL patients. Patients with aPML have a t(15,17) chromosomal translocation.
● Choice D (Stem cell transplant) should be considered for younger individuals who have non-M3 AML.
● Choice E (ATRA and daunorubicin) is the correct answer. This regimen is largely responsible for providing an improved prognosis for aPML compared to non-M3 AML. Sometimes treatment with ATRA can cause fever, pleural effusions, respiratory distress and hypotension. This is known as ATRA syndrome. If the patient develops ATRA syndrome, then the best treatment would be dexamethasone and withdrawal of ATRA.
You can view all the previous ABIM Exam Review Questions of the Week at the Knowmedge Blog. You can also find additional topics and questions directly from the Knowmedge Internal Medicine ABIM Board Exam Review Questions QVault.