Laryngeal paraganglioma: an updated critical review.

Laryngeal paragangliomas are rare submucosal lesions that arise from paraganglion cells located in the false vocal fold and subglottic larynx. To date, 76 recognized cases have been reported in the world literature. Symptoms arise when the lesions become large enough to impair function. Supraglottic paragangliomas cause hoarseness and deglutition disorders, whereas subglottic tumors become symptomatic when they obstruct the airway. Evaluation of these tumors includes obtaining a complete history. Familial paragangliomas and hypertension should be sought but are rarely, if ever, associated with laryngeal paragangliomas. MRI can detect these lesions and permit characterization of the vascularity of the lesion. Adding 111In pentetreotide scanning can distinguish neuroendocrine tumors from other submucosal laryngeal lesions, making the preoperative diagnosis clearer and obviating the need for biopsy. The biggest dilemma regarding laryngeal paragangliomas is making the correct pathologic distinction between paraganglioma, typical carcinoid, atypical carcinoid and medullary thyroid cancer. Immunohistochemical markers, supplementing standard histopathologic evaluation, can distinguish paragangliomas from the aforementioned tumors. This distinction is critical as the prognosis for treated paragangliomas is excellent compared to that for other neuroendocrine neoplasms. Almost all alleged malignant paragangliomas of the larynx are in reality atypical carcinoid tumors that have been misdiagnosed. Treatment should always comprise excision. Thyrotomy has the best chance of achieving a sustained cure without damaging phonation or deglutition. Laser excision has been used successfully but there is no great experience with this modality. Surgery is preferable to radiation for paragangliomas in all locations but especially so in the larynx, due to issues such as swelling, airway protection and destruction of cartilage. With increased clinical suspicion and the use of modern imaging techniques, laryngeal paragangliomas should be routinely diagnosed and treated without loss of laryngeal functions.