Commonest childhood tumor is:
**Core Concept**
Neuroblastoma is a type of cancer that primarily affects children, typically presenting as a solid tumor in the adrenal glands or sympathetic nervous system. This tumor arises from immature nerve cells and is often associated with mutations in the MYCN gene.
**Why the Correct Answer is Right**
The correct answer is Neuroblastoma. It is the most common extracranial solid tumor in children, accounting for approximately 6-10% of all childhood cancers. Neuroblastoma arises from the sympathetic nervous system, which includes the adrenal glands, and is often diagnosed in children under the age of 5. The tumor's growth can be influenced by the MYCN gene, a proto-oncogene that, when mutated, can lead to uncontrolled cell proliferation.
**Why Each Wrong Option is Incorrect**
**Option A:** Medulloblastoma is a type of brain tumor that is more common in children than other brain tumors, but it is not the most common childhood tumor overall.
**Option B:** Rhabdomyosarcoma is a type of soft tissue sarcoma that can occur in children, but it is not as common as Neuroblastoma.
**Option C:** Wilms tumor is a type of kidney cancer that primarily affects children, but it is not the most common childhood tumor.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that Neuroblastoma can present with a variety of symptoms, including abdominal masses, bone pain, and eye abnormalities, and that early diagnosis and treatment are crucial for improving outcomes.
**Correct Answer: C. Neuroblastoma**