Bevacizumab fails to treat temporal paraganglioma: discussion and case illustration

Temporal paragangliomas are highly vascular tumors treated primarily by surgical resection. However, surgery to remove these tumors is associated with significant morbidity, including cranial nerve dysfunction. Interestingly, these tumors have been shown to express vascular endothelial growth factor (VEGF). A variety of tumors expressing VEGF and the VEGF receptor have been shown to reduce in size and vascularity when treated with the VEGF-specific antibody, bevacizumab (Avastin). We hypothesized that paragangliomas may be treated noninvasively with bevacizumab, either as a primary treatment or as a useful adjuvant to surgical resection or radiation. Thus, our aim was to evaluate the effects of bevacizumab on this patient's paraganglioma. A 36-year-old female presented to us with a 3 month history of positional dizziness, light-headedness, and left ear pulsatile tinnitus and hearing loss. She was found to have a temporal paraganglioma (glomus jugulare tumor) on imaging. Histopathology confirmed significant staining for VEGF. This patient was treated with bevacizumab prior to surgical treatment; radiographic imaging at 3 months, however, showed no significant response. We discuss possible reasons for treatment failure.