Case of acquired or pseudo-Pelger-Huët anomaly

Pelger-Huët anomaly (PHA) is a rare benign autosomal-dominant anomaly with an incidence of ∼1 in 6000. It does not cause neutrophilia, but it can cause a false increase in band forms. It should be differentiated from acquired or pseudo-Pelger-Huët anomaly (PPHA), which has similar morphology, however; it is associated with different pathological states like Myelodysplastic syndrome, as well as with certain infections and drugs. We report a case of a 67-year-old Caucasian gentleman with past medical history of rheumatoid arthritis, type II diabetes mellitus and hypothyroidism, who presented with 1 day history of fever (101°F) and night sweats. Medications include ibuprofen, methotrexate, hydroxychloroquine and levothyroxine. Patient denied any other symptoms. His work-up showed normal WBC count (8.6) and increase in bands (24%). The patient was admitted for further evaluation. During the next 2 days, the patient did not have any fever or any new symptoms. Peripheral blood smear was done as part of his work-up for bandemia, showed findings suggestive of PHA. Ibuprofen was discontinued. Follow-up few weeks later showed normal blood smear. Diagnosis of PPHA was made. The presented case showed that we should think of PHA\PPHA in any case with normal total WBC count and significant shift to the lift with no apparent explanation. Looking at smears directly under the microscopes is crucial to make diagnosis.