Unusual Presentation of Myeloid Sarcoma as Thigh Mass

Abstract

IntroductionMyeloid sarcoma (MS) is a tumor containing myeloid blasts, with or without maturation, involving any anatomical site other than the bone marrow. It can occur de novo or following a hematological malignancy. CaseWe report a 6-year-old female who presented with fever and a rapidly enlarging left thigh mass. The initial provisional diagnosis considered was tubercular hip arthritis with an abscess, but imaging investigations suggested neoplastic swelling. A biopsy of the mass showed a malignant small-round cell tumor. Bone marrow aspiration revealed the diagnosis of acute myeloid leukemia without the presence of blasts in the peripheral smear. ConclusionMS is a rare malignancy. The diagnosis is often delayed due to a lack of clinical suspicion and the absence of blasts in peripheral blood. This report aims to enhance the awareness of pediatric nurse practitioners that MS should also be considered as a differential for an extremity mass.