Cytogenetic analysis of a neuroblastoma from a 2-year-old reveals numerous small extrachromosomal chromatin bodies and homogeneously staining regions. These findings represent amplification of which oncogene, and carry what prognostic significance?

• A NTRK1 amplification, associated with poor prognosis
• B HER2 amplification, associated with good prognosis
• C MYCN amplification, associated with poor prognosis ✓
• D ALK amplification, associated with good prognosis

Explanation

Amplification of the MYCN (N-myc) proto-oncogene appears cytogenetically as double minutes (extrachromosomal bodies) and homogeneous staining regions, and is present in roughly 25% of neuroblastomas. MYCN amplification is one of the most important adverse risk factors in neuroblastoma regardless of age or stage. HER2 amplification characterizes a subset of breast and gastric cancers, while ALK alterations in neuroblastoma are gene mutations or fusions rather than amplification and do not define favorable biology.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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