Smear Campaign: Misattribution of Pancytopenia to a Tick-Borne Illness
We report the case of a 51-year-old woman presenting with a targetoid rash and pancytopenia after a tick bite. Initial evaluation was notable for severe neutropenia on the complete blood cell count differential, a positive Lyme IgM antibody, and a peripheral blood smear demonstrating atypical lymphocytes. While her pancytopenia was initially attributed to tick-borne illness, peripheral flow cytometry showed 7% myeloblasts, and a bone marrow biopsy confirmed 60% blasts. The patient was ultimately diagnosed with acute myelogenous leukemia, in addition to early, localized Lyme disease. This case highlights the differential diagnosis for pancytopenia, cytopenia patterns for different tick-borne illnesses, the risk of premature closure in internal medicine, and management of Lyme disease in hosts with altered immunity.
KEY WORDSpancytopenia tick-borne illness Lyme disease acute myelogenous leukemia
The authors acknowledge Maureen Achabe and Elisa Aquilanti for providing the photograph of the peripheral blood smear.
Compliance with Ethical Standards
This work was presented as an oral presentation at the Society of General Internal Medicine New England Regional Meeting, Boston, MA, March 2017, and as a poster presentation at the Society of General Internal Medicine National Meeting, Washington, DC, April 2017.
Conflict of Interest
All authors declare that they have no conflict of interest.
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