Table 1.

Classification of paragangliomas

Glasscock-Jackson classification			Fisch classification		Shamblin classification
	TPG	JPG		JPG		Carotid PG
Type 1	Small mass limited to the promontory	Involves jugular bulb, middle ear, mastoid process	Type A	Limited to middle ear cleft	Type 1	Tumors are localized with minimal vascular attachments. These are easily amenable to complete resection with very little morbidity
Type 2	Tumor completely filling the middle ear	Extends under canal, with or without intracranial extension	Type B	Limited to the tympanomastoid area; cortical bone over jugular bulb intact	Type 2	Tumors partially surround the carotids. These are careful surgical excisions
Type 3	Tumor filling middle ear and mastoid	Extends into petrous apex with or without intracranial extension	Type C (C1-C2-C3)	Involving the infralabyrinthine compartment and petrous apex of the temporal bone	Type 3	Tumors encase the carotids. Surgical resection is difficult and may require major vessel reconstruction
Type 4	Further extension through the EAC or anteriorly to the carotid artery	Extends beyond petrous apex into clivus or infratemporal fossa, with or without intracranial extension	Type D (D1-D2-D3)	Glomus jugular tumors with intracranial extensions

TPG: Tympanic paraganglioma; JPG: Jugular bulb paraganglioma; PG: Paraganglioma; EAC: External auditory canal.