A 34-year-old male in first remission of early T-cell precursor acute lymphoblastic leukemia underwent a 10/10 HLA-matched unrelated donor stem cell transplant. On day +86, he developed adenovirus PCR-positive hemorrhagic cystitis managed with hydration, ribavirin, intravenous immunoglobulin and tapering of immunosuppression. Chimerism analysis showed 100% donor engraftment. Hemoglobin was 78 g/L, total leukocytes 1.1 × 109/L and platelets 86 × 109/L. ~2–3% neutrophils contained 1–3 small, round, discrete, deeply basophilic, hyperchromatic cytoplasmic inclusions reminiscent of erythrocytic Howell-Jolly bodies (Fig. 1). Rare monocytes too contained similar inclusions. Exceptional ones displayed engulfed erythrocytes (Fig. 1, inset). Ferritin was 3200 ng/mL. Triglycerides and fibrinogen were normal. Hemophagocytic lymphohistiocytosis was considered in view of persistent fever, splenomegaly, hyperferritinemia and pancytopenia. Bone marrow was markedly hypocellular without prominent hemophagocytosis or increased blasts. Hemorrhagic cystitis improved with continued therapy. Fever resolved by day +94, urine became clear and inclusions undetectable. However, adenovirus PCR (urine) remained positive.
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