Which orbital tumor is the most common primary pediatric orbital malignancy?

• A. Neuroblastoma
• B. Cavernous hemangioma
• C. Optic nerve glioma
• D. Rhabdomyosarcoma

Answer: (D)

Rhabdomyosarcoma is the most common malignant tumor arising primarily in the pediatric orbit. It comes from primitive mesenchymal cells capable of developing into skeletal muscle, with the embryonal subtype being the most frequent in children. Clinically, it often presents as a rapidly progressive unilateral proptosis with eyelid swelling and sometimes decreased vision, reflecting its fast-growing nature. Early biopsy and prompt, multimodal treatment (chemotherapy, radiotherapy, and sometimes surgery) offer the best chance for cure.

Neuroblastoma can involve the orbit, but typically as a metastatic process rather than a primary orbital tumor. Cavernous hemangioma is a benign vascular tumor and is less common in children as a malignant orbit lesion. Optic nerve glioma does occur in children and is a recognized orbital/optic nerve tumor, but it is not as common as rhabdomyosarcoma when considering primary pediatric orbital malignancies.