A case of MYCN-amplified stage 4 neuroblastoma relapsed with catecholamine-negative tumor mainly composed of MIBG-non-avid component

Abstract

We present a case of stage 4 neuroblastoma of the left adrenal gland with MYCN amplification in a 2.5-year-old boy. At the time of diagnosis, the tumor had a component that was partially negative for ¹²³I-metaiodobenzylguanidine (MIBG) with MYCN amplification. Treatment was completed in accordance with the high-risk protocol, and complete remission was achieved. However, 14 months after treatment completion (at 4.5 years of age), the patient developed a facial nerve palsy. Cancer recurrence was observed in the left cerebellopontine angle, left orbital bone, and bone marrow. The recurrent lesion was weakly positive/negative for MIBG, the urinary catecholamine level was not elevated, and the bone marrow metastatic cells were negative for tyrosine hydroxylase. MIBG-non-avid neuroblastoma has a better prognosis than MIBG-avid neuroblastoma. However, among MIBG-non-avid tumors, non-catecholamine-secreting neuroblastomas have an increased likelihood of containing more undifferentiated and aggressive components and require caution for early relapse.