Case study interpretation—Houston: Case 3

CASE HISTORY A 16-year-old high school sophomore presented to his primary care physician (PCP) with a 5-day history of fever and flu-like symptoms. Despite a course of antibiotics, his symptoms did not improve, and he returned to his PCP where a strep test was performed and was positive, but a low white blood cell count (WBC) was noted. He was sent to the emergency room (ER), where his labs showed the following: WBC: 2.02 10/ll, absolute neutrophil count (ANC) of 750, hemoglobin and hematocrit of 10.8 gm/dl and 29%, respectively, mean corpuscular volume (MCV) of 100.6 femtoliters (FL), and platelets of 193,000/ll. He was evaluated by Hematology/Oncology, and the peripheral smear was reviewed with no abnormal cells seen, and the patient was sent home. A few days later, he represented to his PCP with continued symptoms, and was again transferred to the ER. His ANC had dropped to 500 (other hematological parameters approximately the same), and the patient was admitted for further work up and possible IV antibiotics. Review of a second peripheral smear was also read as negative by Hematology/Oncology. Flow cytometric studies performed on a bone marrow obtained on day 8 following induction therapy had similar findings and is presented below.