A pediatric oncology clinic evaluates four children and adolescents with newly diagnosed malignancies. Based on their clinical presentation and initial diagnostic findings, match each patient to the most characteristic underlying genetic or molecular abnormality.
- A 15-year-old boy with a rapidly expanding maxillary mass and tumor lysis syndrome; biopsy shows a high proliferative index (Ki-67 >99%) with interspersed tangible-body macrophages.Translocation t(8;14) resulting in c-myc overexpression
- A 4-year-old girl with petechiae and bone pain; flow cytometry confirms CD19+, CD10+ lymphoblasts. Karyotype shows a translocation associated with a highly favorable prognosis.Translocation t(12;21) resulting in ETV6-RUNX1 fusion
- A 13-year-old boy with a painful, lytic mid-shaft femur lesion; histopathology demonstrates sheets of undifferentiated cells exhibiting strong membranous CD99 staining.Translocation t(11;22) resulting in EWS-FLI1 fusion
- A 2-year-old boy presenting with periorbital ecchymoses and an irregular abdominal mass crossing the midline; urine homovanillic and vanillylmandelic acid levels are markedly elevated.Amplification of the MYCN (N-myc) proto-oncogene
Answer
The rapidly expanding maxillary mass with macrophages matches t(8;14) (Burkitt lymphoma). The B-ALL with a favorable prognosis matches t(12;21). The diaphyseal femur lesion with CD99+ cells matches t(11;22) (Ewing sarcoma). The abdominal mass with elevated catecholamines matches MYCN amplification (neuroblastoma).
Each pediatric malignancy has a highly stereotyped clinical presentation that correlates precisely with specific molecular and genetic drivers. Burkitt lymphoma requires the t(8;14) c-myc translocation for its explosive growth. Favorable pediatric B-ALL is driven by the t(12;21) ETV6-RUNX1 fusion. Ewing sarcoma relies on the t(11;22) EWS-FLI1 fusion product. Neuroblastoma aggression is closely tied to MYCN amplification.
Step-by-Step Solution
Key Concept
Clinical and molecular correlations of pediatric malignancies