Single Agent Therapy with Bevacizumab for the Treatment of Atypical Choroid Plexus Tumor

Abstract

Introduction Choroid plexus tumors are rare tumors of the brain. They account for 0.3-0.6% of all brain tumors. Fifty percent of these tumors occur in the lateral ventricle, 40% in the fourth ventricle, 5% in the third ventricle, and 5% are multifocal. Grading of choroid plexus tumors is based on World Health Organization (WHO) classification. Choroid plexus papilloma is grade I, atypical choroid plexus papilloma is grade II, and choroid plexus carcinoma is grade III. For both choroid plexus papilloma and choroid plexus carcinoma, age at presentation correlates with the location of the tumor. Lateral ventricle tumors are more common in children less than 10 years old, while fourth ventricle tumors are distributed evenly up to 50 years of age. Choroid plexus papilloma is welldifferentiated and usually has a benign course and carries a good prognosis after complete resection. Occasionally, there can be a malignant transformation to a choroid plexus carcinoma at recurrence. These are aggressive tumors characterized by brisk mitotic activity, increased cellularity, nuclear pleomorphism, focal necrosis, loss of papillary architecture, and invasion of neural tissue. Presenting symptoms often are related to cerebrospinal fluid obstruction, such as headache, diplopia, and ataxia. We present a rare case of atypical choroid plexus papilloma in an adult who was treated with single agent chemotherapy. Case Report A 52-year-old woman was referred for chemotherapy of recurrent atypical choroid plexus papilloma. She initially was diagnosed with choroid plexus papilloma and underwent resection. The tumor recurred on multiple occasions and the patient was treated with surgery (three resections) and stereotactic radiosurgery. The last surgery was thirteen years post diagnosis. The pathology result was positive for atypical choroid plexus papilloma (Figure 1). Her last MRI (Figure 2) showed the recurrence of the tumor in the pons area. Due to the location of the tumor, she was not recommended for surgery and referred to medical oncology for systemic chemotherapy. At relapse, the patient complained of headaches and neuropathic pain in the right neck when rotated. She also had right facial nerve palsy with numbness secondary to previous surgeries.