Opsomyoclonus is encountered as C/F of –

Okay, let's tackle this question. The user is asking about opsomyoclonus as a clinical feature of a certain condition. First, I need to recall what opsomyoclonus is. From what I remember, it's a movement disorder characterized by rapid, irregular muscle jerks, often affecting the eyes and limbs. It's part of a broader category called paraneoplastic syndromes.

Now, the question is asking which condition is associated with opsomyoclonus. The options aren't provided, but the correct answer is supposed to be one of them. Let me think about the common associations. I recall that opsomyoclonus, also known as dancing eyes-dancing feet syndrome, is classically linked with certain tumors. The most common association I remember is with neuroblastoma, especially in children. Another possibility is small cell lung cancer in adults. But which one is more commonly cited in exams?

Wait, there's also a condition called Opsoclonus-Myoclonus Syndrome (OMS), which can be idiopathic or paraneoplastic. In children, the paraneoplastic form is often due to neuroblastoma. In adults, it's more commonly associated with lymphomas, seminomas, or small cell lung cancer. But the primary association, especially in pediatric cases, is neuroblastoma.

So, the correct answer here is likely neuroblastoma. The options might include neuroblastoma, lymphoma, small cell lung cancer, or another tumor. The user didn't list the options, but based on standard questions, neuroblastoma is the most probable correct answer.

I need to make sure that opsomyoclonus is indeed a paraneoplastic syndrome of neuroblastoma. Yes, the key features are the opsoclonus (involuntary eye movements) and myoclonus (muscle jerks), and it's often seen in children with neuroblastoma. Other tumors like lymphoma can cause it too, but neuroblastoma is the classic one.

So, the core concept here is the paraneoplastic syndrome associated with opsomyoclonus. The correct answer is neuroblastoma. The other options would be other tumors that can cause similar syndromes but are less commonly associated. For example, lymphoma or small cell lung cancer might be distractors, but the primary association is neuroblastoma in pediatrics.

I should also check if there's any other tumor that's more commonly linked. No, neuroblastoma is the main one here. The clinical pearl would be that in children, opsomyoclonus is a red flag for neuroblastoma, prompting imaging studies. That's a high-yield fact for exams like NEET PG or USMLE.

**Core Concept**
Opsomyoclonus is a paraneoplastic syndrome characterized by chaotic eye movements (opsoclonus) and muscle jerks (myoclonus), most commonly associated with **neuroblastoma** in children. It results from autoimmune targeting of the nervous system triggered by tumor antigens.

**Why the Correct Answer is Right**
Neuroblastoma, a pediatric tumor of the sympathetic nervous system, is the classic cause of opsomyoclonus-myoclonus syndrome (OMS). Tumor-derived antigens (e.g., GD2, gangliosides) cross-react with neural antigens, inducing

✓ Correct Answer: B. Neuroblastoma