Table 4.

Classifications of HNPGLs

Classification	Localization	Primary Subclass	Secondary Subclass	Tertiary Subclass
Shamblin's	Carotid Body PGL	I: splaying of the carotid bifurcation with little attachment to the carotid vessels	II: partial involvement of the carotid vessels	III: complete involvement of the carotid vessels
Netterville's	Vagal PGL	A: confined to the neck	B: in contact with the jugular foramen	C: extended into or beyond the jugular foramen with or without intracranial extension
Fisch and Mattox's	Tympanic PGL	A: limited to the middle ear cleft	B: limited to the tympanomastoid compartment
	Jugular PGL	C1: located in the jugular foramen, erosion of the carotid foramen	C2: vertical segment of the carotid canal involved C3: horizontal segment of the carotid canal involved C4: foramen lacerum and cavernous sinus involved	De: intracranial extradural extension (De1/2 depending on the displacement of the dura) Di: intracranial intradural extension (Di1/2/3 depending on the depth of invasion into the posterior cranial fossa)