An unusual case of febrile neutropenia: acute myeloid leukemia presenting as myeloid sarcoma of the spleen.

Differential diagnosis of a focal splenic lesion in the context of acute leukemia is quite challenging. A 58-year-old woman presented with a 3-day history of fever and abdominal pain. The results of hematological work-up were consistent with acute myeloblastic leukemia (M2, French-American-British classification). Being susceptible to infection in this leukemic patient with severe neutropenia, a diagnosis of splenic abscess was straightforward, plausibly supported by the radiographic findings. Despite empiric broad-spectrum antibiotic treatment, hyperleukocytosis with resultant pulmonary leukostasis supervened. Histological sections from ultrasound-guided percutaneous core-needle biopsy of the spleen confirmed the diagnosis of myeloid sarcoma. However, delayed leukemia-targeted therapy, unfortunately, resulted in catastrophic mortality. It should be addressed that, even with the advent of modern imaging modalities, there can be a diagnostic pitfall when managing solitary splenic lesion in acute leukemic patients without histological examination. Early recognition with prompt chemotherapeutic intervention can be life saving.