RT Journal Article SR Electronic T1 The Rare Third Branchial Cleft Cyst JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 1804 OP 1806 DO 10.3174/ajnr.A1627 VO 30 IS 9 A1 Joshi, M.J. A1 Provenzano, M.J. A1 Smith, R.J.H. A1 Sato, Y. A1 Smoker, W.R.K. YR 2009 UL http://www.ajnr.org/content/30/9/1804.abstract AB SUMMARY: Third branchial cleft cysts (BCCs) are rare entities that represent abnormal persistence of the branchial apparatus. On CT examination, these cysts appear as homogeneous low-attenuation masses with well-circumscribed margins; on MR imaging, they demonstrate variable signal intensity on T1-weighted images and are hyperintense relative to muscle on T2-weighted images. Definitive treatment is surgical excision. We present a case of a third BCC and describe its diagnosis and treatment.