急性骨髄性白血病の最初の徴候としての両側性眼球突出症：症例報告

Myeloid sarcoma (MS), also known as granulocytic sarcoma or chloroma, is a rare manifestation of acute myeloid leukemia (AML) that occurs concurrently with, following, or rarely before the onset of leukemia. It consists of immature myeloid cells that proliferate in extramedullary tissues. Owing to the rare association between bilateral proptosis and AML, it is often misdiagnosed as other conditions that present with proptosis, such as infections (as in our case), vascular lesions, or tumors, particularly rhabdomyosarcoma and neuroblastoma, creating a diagnostic dilemma.

We report a case of MS that initially presented with bilateral proptosis and was misdiagnosed as orbital cellulitis. A child of Syrian origin presented with rapidly progressive bilateral proptosis that had started 2 weeks prior to admission. Her medical history was unremarkable except for a blood transfusion 2 months earlier. She initially received treatment for suspected conjunctivitis and then for orbital cellulitis with intravenous antibiotics, with no clinical improvement. On examination, she appeared pale and fatigued. Ophthalmic examination revealed severe bilateral eyelid edema with proptosis and conjunctival chemosis.

MS was diagnosed based on laboratory tests, bone marrow examination, and computed tomography imaging. A complete response was achieved dramatically after 1 month of treatment with the standard chemotherapy regimen.

This case highlights the various aspects of AML in children and aims to draw clinicians' attention to the possible diagnosis of AML in a patient with proptosis, which may lead to earlier diagnosis and treatment.

This case raises awareness among clinicians to consider AML in the differential diagnosis of any child with unilateral or bilateral proptosis, even in the absence of systemic symptoms of leukemia.