Unilateral Exophthalmos as the Initial Presentation of Acute Myeloid Leukemia in a Pediatric Patient: A Report of a Rare Case.

Acute myeloid leukemia (AML) is a malignant hematological condition characterized by the uncontrolled proliferation of immature myeloid cells in the bone marrow, which disrupts the normal production of blood cells. Although it is a relatively rare subtype of pediatric acute leukemia, it is a significant cause of leukemia-related mortality in children. Ocular involvement in acute leukemias, though uncommon, can be a revealing sign of the disease, sometimes presenting as either an initial or secondary manifestation, especially during relapse. We report the case of a five-year-old child presenting with progressive unilateral exophthalmos associated with fever, anemia, and chest pain, signs of general deterioration. Examinations revealed leukocytosis and circulating blasts, suggesting acute leukemia. A bone marrow aspirate confirmed the diagnosis of AML, subtype 2, with multilineage dysplasia. Orbital imaging showed exophthalmos associated with swelling of the lacrimal gland and infiltration of the extraconical fat. Chemotherapy treatment led to complete remission. Ocular manifestations, particularly exophthalmos, are frequently associated with AML and can indicate an aggressive form of the disease or extramedullary localization. Although this presentation generally has a poor prognosis, our case demonstrated a favorable outcome, which is exceptional in the literature. This case underscores the importance of considering leukemia in the differential diagnosis of unexplained exophthalmos in children and the need for rapid diagnostic testing, including bone marrow aspiration, to confirm the disease. Early recognition and appropriate treatment are crucial for improving prognosis.