Article Type : Review Article
Title :   Acute Myeloid Leukemia Presenting as Orbital Mass: A Rare Case Report
Authors :   Sonal Muley
Abstract :   Acute Myeloid Leukemia (AML) is a hematologic malignancy characterized by clonal proliferation of myeloid precursors. Orbital involvement as an initial presentation is rare and may mimic other common pediatric orbital tumors. We report a rare case of AML presenting with unilateral proptosis and orbital mass in a young child, where cytological and histopathological evaluation led to the diagnosis. This case underscores the importance of considering hematologic malignancies in the differential diagnosis of orbital masses, especially in children.
Introduction :   Acute Myeloid Leukemia (AML) typically presents with systemic features such as fatigue, pallor, bleeding, and infections due to bone marrow failure. However, extramedullary manifestations like granulocytic sarcoma (also called myeloid sarcoma) may occur and can sometimes be the initial presentation, particularly in pediatric patients. Orbital involvement by AML is uncommon and can present as unilateral or bilateral proptosis. The rarity of this presentation may delay diagnosis, making early identification and confirmation critical.
Review of Literature :  A 6-year-old male child presented to the ophthalmology department with complaints of progressive swelling and protrusion of the right eye over the past 2 weeks, associated with mild pain and reduced eye movement. There was no history of trauma, fever, or vision loss. On examination: Right-sided axial proptosis Restricted ocular motility Conjunctival chemosis and mild periorbital edema No lymphadenopathy or hepatosplenomegaly at presentation Investigations: Complete blood count revealed mild anemia (Hb 9.5 g/dL), leukocytosis (TLC 28,000/mm³), and thrombocytopenia (platelets 85,000/mm³) Peripheral smear showed blasts with high nuclear-to-cytoplasmic ratio and prominent nucleoli CT orbit: well-defined enhancing soft tissue mass in the right orbit involving the lateral wall and superior rectus muscle FNAC of orbital mass: showed atypical mononuclear cells with features suggestive of leukemic infiltration Bone marrow aspiration and biopsy confirmed diagnosis of Acute Myeloid Leukemia (FAB M2 subtype) The patient was referred to pediatric oncology and initiated on systemic chemotherapy as per AML protocol. The orbital mass showed significant regression after two cycles of chemotherapy.
Discussion :  Orbital involvement in AML is most often due to granulocytic sarcoma, a tumor composed of immature myeloid cells occurring at extramedullary sites. It is more frequent in children and can occur before or during the course of AML. Orbital granulocytic sarcomas may clinically mimic rhabdomyosarcoma, lymphoma, or infectious orbital cellulitis. In our case, the orbital mass preceded the hematological diagnosis of AML, which is rare but has been documented. Imaging studies help localize the mass, while cytology and immunohistochemistry are crucial for definitive diagnosis. Treatment involves systemic chemotherapy for AML, with or without local radiotherapy. Early diagnosis and prompt initiation of chemotherapy can lead to complete regression of the orbital lesion and better outcomes.
Conclusion :  AML presenting as an orbital mass is rare but should be considered in the differential diagnosis of pediatric proptosis. Early cytological or biopsy evaluation, supported by hematological workup, can lead to prompt diagnosis and treatment, thereby avoiding unnecessary surgical interventions and improving prognosis.
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