Tumor Classification

Glomus jugulare tumors are the most common tumors of the jugular foramen. Jugular schwannomas and meningiomas, although uncommon, are the other most common tumors affecting the jugular foramen, some series reporting the former and other series reporting the latter as the second most common.2'14'16 Chordoma,17'18 chondrosarcoma,16'19 chondroblastoma,16 cholesterol granuloma,20 epidermoid cyst,20 parotid neoplasm,16 adenocarcinoma,16 osteoblastoma,16 metastasis,21 plasmacytoma,22 sarcoidosis,23 fibrous dysplasia,24 chondromyxoid fibroma,25 non-Hodgkin's lymphoma,26 and amy-loidoma27 are among the other types of lesions reported in the jugular foramen.

Tumors of the jugular foramen may be either intrinsic, arising from within the foramen, or extrinsic, secondarily extending into the jugular foramen.14 Glomus jugulare is the classic intrinsic jugular foramen tumor, constituting 56 to 77% of jugular foramen tumors in reported series.14 Schwannomas and meningiomas rarely arise as primarily intrinsic jugular foramen tumors.14 Extrinsic tumors can penetrate the jugular foramen from four different directions: (1) superiorly, as a downward extension of intracranial schwannomas and meningiomas; (2) inferiorly, as an upward extension of cervical tumors such as glomus vagale tumors, adenocarcinomas, and schwannomas arising in the parapharyngeal space; (3) medially, such as chordomas and chondrosarcomas of the petrocli-val region; and (4) laterally, from invasive temporal bone tumors such as squamous cell carcinoma and adenomatous

tumors.

TABLE 82-1

Fisch Classification of Glomus Tumors*

TABLE 82-1

Fisch Classification of Glomus Tumors*

Class

Description

A

Tympanic (4/23)

B

Tympanomastoid (7/23)

C

Infralabyrinthine (12/23)

D

Intracranial (1/12, recurrence of pt. with type C)

D1

< 2 cm

D2

> 2 cm

*From Oldring and Fisch37 and Jenkins and Fisch.38

Series data: 23 patients, 5 M: 18 F, mean age 48 years, range 20-69.

*From Oldring and Fisch37 and Jenkins and Fisch.38

Series data: 23 patients, 5 M: 18 F, mean age 48 years, range 20-69.

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