Case of spontaneous regression of carotid body tumor in a SDHD mutant: a discussion on potential mechanisms based on a review of the literature

BACKGROUND: Head and neck paragangliomas are tumors associated with the parasympathetic nerve system and typically show an indolent growth pattern. Therefore a conservative management strategy is considered in selected cases. METHODS AND RESULTS: We present a case of a female patient who presented in 2003 with bilateral carotid body tumors and a tympanic tumor, associated with a mutation in the succinate dehydrogenase -sub-unit-D (SDHD). She was operated on the right carotid body tumor and the tympanic tumor. Thereafter the follow-up was performed with MR examinations at 2-year intervals. After an initial stable phase, over the last 3 years a spontaneous near-total regression of the contralateral carotid body tumor was observed, with only subtle rest-abnormalities visible in 2011. CONCLUSIONS: The present case underlines the indolent growth pattern of head and neck paragangliomas and for the first time describes a rare manifestation of spontaneous regression of a carotid body tumor. The literature was reviewed to discuss this phenomenon.