C. Examine the abdomen during the EUA
The differential diagnosis of an orbital mass in a toddler includes dermoid cyst, infantile hemangioma, subperiosteal hematoma, orbital abscess, rhabdomyosarcoma, leukemia (chloroma), neuroblastoma, venous-lymphatic malformation, histiocytosis, and infantile fibromatosis.1 Aspiration of the lesion (choice A) would be useful in an abscess or a cystic lesion but not in a solid tumor. Ordering orbital magnetic resonance imaging would be a better choice than computed tomography (choice B) because of radiation concerns in a child. Referring the patient for an orbital biopsy (choice D) would be appropriate but could delay treatment in a potentially life-threatening lesion. An abdominal examination (choice C) detected a mass and immediately directed subsequent diagnostic testing and treatment because of the high probability of a metastatic neuroblastoma.