A Toddler with Unilateral Eye Swelling

Introduction: Pediatric eye swelling is a common emergency department (ED) presentation. Underlying etiology is mostly local (allergy, insect bite, trauma, and infection) but at times can be secondary to a systemic process (nephrotic syndrome, malignancy). We discuss a patient who presented with an acute onset atraumatic left eye swelling and was subsequently diagnosed with acute myeloid leukemia (AML).

Case Description: A 17-month-old female with no past medical history presented to the ED with 1 day history of left eyelid swelling. Mother denied any eye redness, drainage, fever, trauma, bites, or recent illness. Patient’s vital signs were within normal limits. Physical examination revealed left lower periorbital swelling associated with erythema and tenderness. There was no conjunctival injection, drainage, chemosis, proptosis or any signs of trauma. Pupils were equal, round and reactive. Extraocular movements were intact. The rest of her examination was normal. Patient was discharged on oral antibiotics with a presumptive diagnosis of preseptal cellulitis. Patient returned to the ED the following day because of worsening left eye swelling. Eye examination was limited due to significant periorbital swelling. Differential at this time included worsening preseptal cellulitis versus orbital cellulitis. Ophthalmology was consulted and patient was admitted on IV antibiotics. Complete Blood Count (CBC) with differential showed hemoglobin of 9.7 gm/dL, White blood count of 36.6 K/CUMM, Platelets 92 K/CUMM and Absolute lymphocyte count of 26 K/CUMM. C-reactive protein (CRP) was elevated at 51.4 mg/L. Comprehensive Metabolic Panel (CMP) was unremarkable. Computed tomography (CT) of the orbits showed left preseptal cellulitis and minimal post septal extraconal cellulitis. Repeat CBC showed worsening bicytopenia with anemia (8.1gm/dL) and thrombocytopenia (37 K/CUMM). Pediatric Hematology and Oncology was consulted. Peripheral smear revealed multiple blasts. Magnetic resonance imaging (MRI) orbits showed 0.1 x 0.6 x 0.6-centimeter heterogeneous and hypointense enhancing lesion in the left pre-septal region suggestive of leukemic infiltration also known as chloroma. Bone marrow aspiration and flow cytometry confirmed the diagnosis of AML.

Discussion: Chloroma, an extramedullary proliferation of immature myeloid precursors, is a rare manifestation of AML with a reported incidence of 2.5-9%. It commonly occurs concurrently with AML but may present as a precursor of blast transformation or signify relapse. Clinical presentation is variable and site dependent. Commonly involved sites include subperiosteal bone structures of the skull, paranasal sinuses, sternum, ribs, vertebrae and pelvis; lymph nodes and skin are also common sites. Definitive diagnosis is usually based on immunohistochemistry. Prognostic implication of chloroma in AML remains uncertain. Irrespective of the site or bone marrow status, chloroma is treated by systemic chemotherapy.

Conclusion: Awareness of pediatric eye swelling as a presenting sign of hematological malignancy is essential for clinicians to enable them to consider uncommon conditions such as chloroma in their differential diagnosis.