123I-MIBG SPECT/CT Reveals Solitary Dorsal Root Ganglion Metastasis From Neuroblastoma Mimicking Schwannoma on MRI

A 6-year-old girl with high-risk neuroblastoma achieved a complete response following multimodal therapy. During routine post-therapeutic surveillance, ¹²³ I-MIBG SPECT/CT revealed progressive focal tracer uptake within the right T8–T9 intervertebral foramen. Serial imaging demonstrated interval enlargement of the lesion. On contrast-enhanced MRI, the mass exhibited homogeneous hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and intense, uniform enhancement after intravenous gadolinium administration. Radiologic assessment initially favored a schwannoma. Histopathologic examination of the resected specimen confirmed metastatic neuroblastoma involving the dorsal root ganglion.