Which of the following is the commonest malignancy causing bilateral proptosis in the pediatric population?
High-Yield Explanation
The common causes of bilateral proptosis include granulocytic sarcoma due to AML / Myelodysplastic syndrome and metastatic neuroblastoma. Rhabdomyosarcoma and retinoblastoma rarely produce bilateral proptosis. Causes of bilateral proptosis include: 1. Developmental anomalies of the skull: craniofacial dysostosis e.g., oxycephaly (tower skull). 2. Osteopathies: Osteitis deformans, rickets, and acromegaly. 3. Inflammatory conditions: Mikulicz's syndrome and late stage of cavernous sinus thrombosis. 4. Endocrinal exophthalmos: It may be thyrotoxic or thyrotropic. 5. Tumors: These include symmetrical lymphoma or lymphosarcoma, secondaries from neuroblastoma, nephroblastoma, Ewing's sarcoma and leukemic infiltration. 6. Systemic diseases: Histiocytosis, systemic amyloidosis, xanthomatosis and Wegener's granulomatosis. The most common malignancy causing unilateral proptosis in children: In India - Retinoblastoma In Western population - Rhabdomyosarcoma The most common primary orbital malignancy in children - Rhabdomyosarcoma The most common metastatic orbital malignancy in children - Neuroblastoma Reference : Khurana; 4th edition; Page no: 381