Recurrent Solitary Pleural Metastasis Originating From Neuroblastoma as Demonstrated by 123I-MIBG Scan

An 8-year-old boy with high-risk neuroblastoma underwent routine follow-up 123I-MIBG scan, which revealed abnormal 123I-MIBG accumulation in right pleura, suggestive of potential metastasis. Histopathologic examination of the biopsy specimen confirmed the presence of pleural metastasis. The patient subsequently received four cycles of chemotherapy. A follow-up 123I-MIBG scan after chemotherapy demonstrated no abnormal MIBG uptake, indicating remission of the pleural metastasis. However, 6 months later, a subsequent 123I-MIBG scan revealed recurrent abnormal MIBG uptake in the right pleura at the same location as the initial recurrence. Surgical pathology confirmed the diagnosis of recurrent pleural metastasis.