Prenatally Detected Neonatal Neuroblastoma Associated with Achondroplasia and an SDHA Variant

Background: Neuroblastoma is the most common extracranial solid tumor in infancy and demonstrates marked clinical heterogeneity. To our knowledge, this is one of the very few reported cases of neonatal neuroblastoma associated with genetically confirmed achondroplasia and an additional SDHA variant. Case Presentation: We describe a male neonate with a prenatally detected right-sided suprarenal mass and skeletal abnormalities suggestive of achondroplasia. Postnatal evaluation was consistent with localized neuroblastoma, which was classified as low risk according to the available clinical documentation. Despite the initially favorable clinical risk profile, the tumor showed unexpected progression after initial chemotherapy, requiring treatment intensification and subsequent surgical resection. Next-generation sequencing identified a pathogenic FGFR3 c.1138G>A (p.Gly380Arg) variant confirming achondroplasia and an SDHA c.704T>C (p.Ile235Thr) variant of uncertain significance. At follow-up, the patient remained free of disease recurrence. Conclusions: This case expands the limited evidence on the coexistence of neonatal neuroblastoma and achondroplasia and highlights the potential value of comprehensive genomic testing in patients with atypical clinical behavior. It also demonstrates that an initially favorable clinical risk profile does not invariably predict subsequent disease behavior, emphasizing the importance of integrating clinical, radiological, and molecular findings in individualized patient management.