[Imaging evaluation of the cases with tympanicum and pulsatile tinnitus].

OBJECTIVE

To analyze the CT and MRI features of glomus tympanicum tumors accompanied with tympanitis and evaluate the diagnostic value of CT and MRI in order to improve the cognition for the disease.

METHODS

The clinical materials and images of 8 patients with the symptoms of pulsatile tinnitus and hearing loss in whom glomus tympanicum tumors with tympanitis surgically and pathologically confirmed were retrospectively reviewed. The characteristics and diagnostic value of CT and MR imaging were summarized.

RESULTS

By CT examination the lesions in middle ear and mastoid were preoperatively diagnosed as tympanitis in five cases and only in three cases the glomus tympanicum tumors were suspected. In six patients underwent MR examination the lesions were all preoperatively diagnosed as glomus tympanicum tumors accompanied with tympanitis. HRCT scanning of the temporal bone in all patients showed the soft tissue lesions in the tympanic cavity and mastoid, and the caritas tympanic were mostly (n = 3) or completely (n = 5) occupied by soft tissue lesions, but the auditory ossicles were all without destruction. Contrast-enhanced axial CT scanning performed in five cases showed less soft tissue mass on the cochlear promontory, and the size of mass was less than that observed in MR imaging. MR T(1)-weighted imaging showed the presence of isointense lesions in middle ear and isointense (n = 3) or hyperintense (n = 3) lesions in mastoid. On T(2)-weighted imaging the lesions with slight hyperintense were viewed in the middle ear and the lesions with hyperintense in mastoid. T(1)-weighted gadolinium-enhanced MRI showed the masses in tympanum were markedly increased enhancement, but the lesions in mastoid without enhancement. MRI and CT imaging revealed the masses in six cases of eight extending to the eustachian tube.

CONCLUSIONS

When the glomus tympanicum tumor was accompanied with tympanitis the tumor could be misdiagnosed or missed only by CT examination. The patients with pulsatile tinnitus should be taken seriously. MRI with contrast-enhancement is superior to CT in the preoperative diagnosis and accurately evaluation for the glomus tympanicum tumors with tympanitis.