The patient is a 20 year old female with no significant past medical history who presented from another hospital . 2 weeks prior to transfer she developed a headache and sore throat with associated fevers, chills, and a temp of 101-102 degrees F.  In initial work up she was negative for streptococcal infection. Two weeks prior to her symptoms, she traveled to Portage, Wisconsin , where swam in the local lake. Three months prior, she traveled  to Ireland where she was in contact with donkeys. At the OSH worked up and found to have worsening bicytopenia, transaminitis, and hyperbilirubinemia. She was started on empiric antibiotic therapy. On the morning of transfer, she developed a papular bullous rash on her mid-thighs, mildly increased liver enzymes, increased LDH and total bilirubin of 9.4mg/dL. She was then transferred to  our hospital for escalation of care and workup  for HUS, hemolytic anemia, or other causes.

On initial admission she had mild fever, headaches, photophobia with reduced vision, phonophobia, fevers, chills, nausea and vomiting, jaundice, and dark urine. Initial labs showed a hemoglobin concentration of 8.4g/dL, with positive direct antiglobulin test, elevated LDH, and low haptoglobin consistent with autoimmune hemolysis. CSF studies were within normal limits, and bone marrow biopsy and aspiration was performed.

At the time of biopsy CBC showed:

WBC (th/mcL): ________ 3.35 (L)

RBC (M/mcL):_________ 2.54 (L)

Hemoglobin (g/dL):_____ 9.2 (L)

Hematocrit (%):  _______ 24.5 (L)

MCV (fL):_____________ 96.5

MCH (pg): ____________ 36.2 (H)

MCHC (g/dL): _________ 37.6 (H)

RDW (%): ____________ 20.6 (H)

Platelets (th/mcL):______ 98 (L)

Neutrophils (th/mcL): ___ 1.37 (L)

Immat. grans. (th/mcL): _ 0.04

Lymphocytes (th/mcL):__ 1.71

Monocytes (th/mcL):____ 0.18

Eosinophils (th/mcL): ___ 0.02

Basophils (th/mcL):_____ 0.03

The blood smear showed an increased fraction of atypical lymphocytes (A).

Subsequent to marrow biopsy, EBV IgM titer results were positive, indicating a diagnosis of infectious mononucleosis, antibiotics were withheld, and all of her symptoms improved spontaneously.

The biopsy showed normal hematopoiesis with occasional granulomas, including lipogranulomas and fibrin ring granulomas. Occasional clusters of activated lymphocytes were evident near the granulomas, and scattered EBER+ cells were identified.