ALLERGIC FUNGAL SINUSITIS WITH CRANIAL BASE EROSION

Background. Allergic fungal sinusitis (AFS) usually follows a slow, no naggressive course. However, massive bone destruction can occur, with extension of the disease process outside of the confines of the sinuse s. Methods. Our series of 28 cases of AFS was reviewed. We identified 6 cases of AFS with definite radiographic evidence of skull base erosi on. Results. Histologic diagnostic criteria for AFS were present in al l 6 cases. All patients were managed with surgery, most recently conse rvative endoscopic surgery. An earlier patient underwent dural resecti on. Antibiotics were used in all patients, but no antifungal agents we re administered. No patient has had a permanent neurologic complicatio n, although one was seen with abducens palsy. There have been no cereb rospinal fluid (CSF) leaks. All 6 cases also had orbital bone erosion, but none has had permanent ophthalmologic sequelae. All patients were initially suspected to have a neoplastic disease. Conclusions. We pro pose a new diagnostic entity, ''skull base allergic fungal sinusitis'' (SBAFS), which incorporates the histologic diagnostic criteria of AFS with the computed tomographic (CT) criteria of bone erosion. Biopsy i s necessary to rule out invasive fungus or tumor. Otolaryngologists, o phthalmologists, and neurosurgeons should be familiar with SBAFS so th at systemic antifungal agents, craniotomy, and dural resection-which m ight initially appear necessary-can be avoided. Endoscopic surgical de bridement and drainage combined with topical steroids can lead to reso lution of disease, even in the presence of marked bone erosion and cra nial neuropathy.