Neuroblastoma develops from neural crest cells that normally form the sympathetic nervous system. Tumours may occur anywhere along the sympathetic chain, including the neck, chest, abdomen, pelvis, and especially the adrenal gland. Many neuroblastomas produce catecholamines, so diagnostic testing often includes urinary catecholamine metabolites such as vanillylmandelic acid, or VMA, and homovanillic acid, or HVA. Tumour behaviour is highly variable: some infant tumours mature or regress, while high-risk tumours may metastasize early to bone, bone marrow, liver, lymph nodes, or skin. Key tumour biology markers include: MYCN amplification: associated with aggressive disease. 11q aberration: adverse prognostic marker in risk classification. Tumour ploidy and segmental chromosomal abnormalities: used in risk stratification. Histology: favourable versus unfavourable histopathology. For Canadian NP practice / CNPLE-aligned preparation (Canada), items rarely announce the topic in the first sentence. Anchor to objective data, trajectory, and the safest next step for the role named in the stem before distractors compete. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line; scope...