FIBROSING INFLAMMATORY PSEUDOTUMORS OF THE CENTRAL SKULL BASE

The most important step in the differential diagnosis of mass lesions of the central skull base is to rule out malignant neoplasms. However, nonneoplastic lesions, such as infections or nonspecific inflammatory lesions of the skull base, can mimic malignant processes, In this stu dy, the authors analyzed seven cases of nonneoplastic noninfectious ma ss-forming lesions involving the central skull base. In most cases, ma lignant processes were suspected at the initial phase of diagnostic wo rk-up, but subsequent histologic examinations revealed that these lesi ons consisted of inflammatory cells and fibrosis without neoplastic ce lls. Common manifestations were pain and other neurological symptoms r elated to the involved anatomical sites. A variety of neurological dys functions of the cranial nerves not including the olfactory and spinal accessory nerves were observed, No patient developed separate lesions outside the head and neck region. After the pathologic diagnosis, mos t of the patients were treated with oral steroid therapy, with initial doses of prednisolone, 60 to 100 mg/d, It was difficult to relate res ponsiveness to steroid therapy with the histologic degree of sclerosis , fibrosis, or chronicity of the disease in these cases. Otolaryngolog ists should be aware of this disease when making treatment decisions f or their patients with skull base lesions.