Neuroblastoma-good prognostic factor is-
**Core Concept**
Neuroblastoma is a type of childhood cancer that arises from the sympathetic nervous system, specifically from the adrenal glands or the sympathetic nervous system ganglia. The prognosis of neuroblastoma is influenced by various factors, including age at diagnosis, stage of the disease, and biological tumor characteristics.
**Why the Correct Answer is Right**
One of the most significant prognostic factors in neuroblastoma is the presence of **N-myc amplification**. Tumors with N-myc amplification tend to have a more aggressive course and a poorer prognosis. However, the absence of N-myc amplification is associated with a better prognosis, particularly in infants, where the disease often spontaneously regresses. This is because infants tend to have a more favorable biology, including a lower likelihood of N-myc amplification and a higher likelihood of spontaneous regression.
**Why Each Wrong Option is Incorrect**
**Option A:** Age at diagnosis is an important prognostic factor in neuroblastoma, but it is not the best answer choice. While infants tend to have a better prognosis than older children, age alone is not a reliable predictor of outcome.
**Option B:** Stage of the disease is a critical prognostic factor in neuroblastoma, with advanced-stage disease having a poorer prognosis. However, stage is not the best answer choice, as it does not capture the underlying biology of the tumor.
**Option C:** Histopathological features, such as the presence of ganglioneuroblastoma or gangliosidosis, may influence prognosis, but they are not the most reliable prognostic factor in neuroblastoma.
**Clinical Pearl / High-Yield Fact**
Infants with neuroblastoma tend to have a better prognosis than older children, particularly if they have a tumor with a favorable biology, such as the absence of N-myc amplification.
**Correct Answer: D. Absence of N-myc amplification.**