Table 2.

Classification of jugulotympanic paragangliomas according to Fisch and Mattox.

Class	Location and extension of paraganglioma
A	Paragangliomas that arise along the tympanic plexus on promontory
B	Paragangliomas with invasion of the hypotympanon; cortical bone over jugular bulb intact
C1	Paragangliomas with erosion of the carotid foramen
C2	Paragangliomas with destruction of the vertical carotid canal
C3	Paragangliomas with involvement of the horizontal portion of the carotid canal; foramen lacerum intact
C4	Paragangliomas with invasion of the foramen lacerum and cavernous sinus
De 1/2	Paragangliomas with intracranial but extradural extension; De1/2 according to displacement of the dura(De1  =  less than 2 cm, De2  =  more than 2 cm)
Di 1/2/3	Paragangliomas with intracranial and intradural extension; Di1/2/3 according to depth of invasion into the posterior cranial fossa(Di1  =  less than 2 cm, Di 2 =  between 2 and 4 cm, Di3  =  more than 4 cm)