Leukemoid reaction
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Leukemoid reaction
USMLE® Step 1 style questions USMLE
A 47-year-old man comes to the office due to 2 days of sore throat, purulent nasal discharge and facial pain. Past medical history is significant for several sinus infections over the past 6 months, all of which resolved with oral antibiotics. Temperature is 38.5°C (101.4°F), pulse is 80/minute, respirations are 19/minute, and blood pressure is 130/70 mmHg. Physical examination shows pharyngeal erythema and maxillary sinus tenderness. There is no lymphadenopathy. Laboratory results are as follows:
Laboratory value | Result |
Complete blood count | |
Hemoglobin | 10 g/dL |
Platelets | 600,000/mm3 |
Leukocytes | 100,100/mm3 |
Neutrophils | 40% |
Myelocytes | 32% |
Metamyelocytes | 10% |
Band forms | 1% |
Blast cells | 1% |
Lymphocytes | 7% |
Leukemoid reaction exam links
Leukemoid reaction refers to an increase in white blood cell count, specifically above 50,000 cells/mm �, due to causes other than leukemia. Leukemoid reactions can occur as a response to stress or infection, and can mimic symptoms of leukemia, such as fatigue, weight loss, and bruising. Distinction between the two needs lab tests, which show elevated neutrophils (suggestive of an acute inflammatory process) in case of leukemoid reaction, and the absence of dysplastic cells (seen in leukemia).