G. Lanzino et al., PARASELLAR MENINGIOMAS - INCIDENCE OF INVOLVEMENT OF EXTRACAVERNOUS STRUCTURES AS DETERMINED BY MAGNETIC-RESONANCE AND COMPUTED-TOMOGRAPHY, Skull base surgery, 3(3), 1993, pp. 152-158
Parasellar meningiomas frequently extend beyond the cavernous sinus in
to adjacent structures. In order to determine the incidence of involve
ment of adjacent sites, we retrospectively evaluated the computed tomo
graphy and nuclear magnetic resonance scans of 65 consecutive patients
with meningiomas invading the cavernous sinus. Thirteen nearby anatom
ic sites were analyzed for tumor involvement. The sites most frequentl
y involved were the lateral sphenoid sinus wall (93%), the ipsilateral
petrous apex (70%), the ipsilateral posterior petrous bone surface (5
9%), the sella (59%), the intracranial clival surface (44%), and the s
uprasellar cistern (41%). The sella, clival bone marrow, orbital apex,
pterygopalatine fossa, and prestyloid parapharyngeal space were more
commonly involved in recurrent tumors. Lesions were also subdivided in
to five groups according to whether or not they involved only one part
of the cavernous sinus (grade 1), two parts of the cavernous sinus (g
rade 2), surrounded the cavernous carotid artery (grade 3), surrounded
and narrowed the cavernous carotid artery (grade 4), or involved both
sides of the cavernous sinus (grade 5). Among the 63 cases that could
be assigned to a category, seven were grade 1 lesions, 13 were grade
2, 13 were grade 3,16 were grade 4, and 14 were grade 5. Tumor grade i
s helpful in predicting the difficulty of resection of the cavernous c
omponent of the tumor. The incidence of involvement of adjacent sites
is also helpful in assessment of imaging studies and in planning the m
ost appropriate surgical approach.