This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Opsoclonus - Myoclonus is a phenomenon seen in ? 
Select and explain. 
A. Wilms tumor, B. Neuroblastoma, C. Meningioma, D. Coical tuberculoma
B: Neuroblastoma
Answer: B: Neuroblastoma 
Explanation: Ans. is 'b' i.e., Neuroblastoma Opsoclonus is a disorder of eye movement characterized by involuntary, chaotic saccades that occur in all directions of gaze. It is frequently associated with myoclonus and ataxia. Opsoclonus-myoclonus may be cancer-related or idiopathic. When the cause is paraneoplastic, the tumors involved are usually cancer of the lung and breast in adults and neuroblastoma in children.