Retroperitoneal Neuroblastoma Metastatic to the Cerebellopontine Angle

Abstract

Neuroblastoma is the most common extracranial solid tumor in children. Survival rates have improved because of advances in treatment with aggressive chemotherapy and autologous bone marrow transplantation. Usual sites of recurrence and/or metastases include the site of the primary tumor, residual gross disease, bones, bone marrow, liver, and lungs. Central nervous system metastases have been regarded as uncommon; however, it is being increasingly diagnosed due to prolonged overall survival rates. Herein, we describe a 3-year-old boy with stage 4 primary adrenal gland neuroblastoma that metastasized to the pyramidal bone and rapidly extended into the cerebellopontine cistern while he was in the course of therapy for idiopathic thrombocytopenic purpura. He underwent an emergent debulking surgery, and the cerebellopontine angle metastatic lesion almost completely resolved after radical chemotherapy. Although our case is only the fourth case report of the metastatic cerebellopontine angle neuroblastoma in the literature, all clinicians involved in the treatment of pediatric neoplasms need to take this rare disease into consideration as a potential differential diagnosis.Key Words: metastatic neuroblastoma, rapid growth, cerebellopontine angle tumor (Neurosurg Q 2015;25:267-270) C erebellopontine angle (CPA) tumors comprise about 8% to 10% of all intracranial tumors. The majority of these tumors are vestibular schwannoma, followed in predominance by meningioma and epidermoid cyst. Metastases to the CPA are rare, representing only 0.2% to 2.0% of all CPA lesions, and are known to arise from primary neoplasm of the colon, breast, and melanoma. 1-4 Differentiation of these neoplasms from other less common lesions of the CPA is difficult due to the similarity of presenting signs and symptoms. However, distinguishing among lesions is essential for determining prognosis and formulating an appropriate therapeutic protocol. In contrast, neuroblastoma originates from neural crest cells of the adrenal medulla or sympathetic ganglia and is the most common solid extracranial tumor in children, accounting for approximately 7% of all pediatric cancers. 5,6 Over 70% of neuroblastoma patients have progressed to disseminated disease by the time of diagnosis, and these patients have a poor prognosis. 6 Common sites of distant metastases are the bone marrow, bony cortex, liver, lymph nodes, subcutaneous tissue, and intraorbital space. 7,8 Central nervous system metastasis occurs rarely, in only 1% to 16% of cases. Furthermore, metastatic neuroblastoma presenting as a CPA mass is quite rare. Herein, we report a case with intra-abdominal neuroblastoma that unexpectedly spreaded to the CPA. CASE DESCRIPTIONA 3-year-old boy with 1-year therapeutic history for idiopathic thrombocytopenic purpura (ITP) suddenly developed left facial palsy. Before this symptom, he had 4-months history of swaying to the left accompanied by progressive left facial nerve palsy. Headache and somnolence were present for a week before facial palsy developed. Neur...