Extracranial sinonasal tract meningiomas - A clinicopathologic study of 30cases with a review of the literature

Extracranial meningiomas of the sinonasal tract are rare tumors. These tumo rs are frequently misclassified, resulting in inappropriate clinical manage ment. To date, there has been no comprehensive study to evaluate the clinic opathologic aspects of meningioma in these anatomic sites. Thirty cases of sinonasal tract meningiomas diagnosed between 1970 and 1992 were retrieved from the files of the Otorhinolaryngic Registry of the AFIP. Histologic fea tures were reviewed, immunohistochemical studies were performed, patient fo llow up was obtained, and the results were statistically analyzed. The pati ents included 15 females and 15 males, aged 13 to 88 years (mean, 47.6 yrs) . Patients presented clinically with a mass, epistaxis, sinusitis, pain, vi sual changes, or nasal obstruction, dependent on the anatomic site of invol vement. Symptoms were present for an average of 31.1 months. The tumors aff ected the nasal cavity (n = 14), nasopharynx (n = 3), frontal sinus (n = 2) , sphenoid sinus in = 2), or a combination of the nasal cavity and ethmoid. frontal, sphenoid, and/or maxillary sinuses(n = 9). The tumors ranged in s ize from 1.0 to 8.0 cm in greatest dimension (mean, 3.5 cm). Radiographic s tudies demonstrated a central nervous system connection in six cases. The t umors often eroded the bones of the sinuses (n = 18) and involved the surro unding soft tissues, the orbit, and occasionally the base of the skull. His tologically, the tumors demonstrated features similar to intracranial menin giomas. The majority were of the meningothelial type(n = 23), although ther e were three atypical meningiomas. Immunohistochemical studies confirmed th e diagnosis of meningioma with positive reactions for epithelial membrane a ntigen (EMA) and vimentin (all tested). The differential diagnosis includes paraganglioma, carcinoma, melanoma, psammomatoid ossifying fibroma, and an giofibroma. Surgical excision was used in all patients. Three patients died with recurrent disease (mean, 1.2 yrs), one was alive with recurrent disea se (25.6 years), and the remaining 24 patients were alive or had died of un related causes (mean, 13.9 yrs) at the time of last follow up (two patients were lost to follow up). Extracranial sinonasal tract meningiomas are rare tumors which need to be considered in the differential diagnosis of sinona sal tumors. A whorled growth pattern and psammoma bodies, combined with pos itive EMA and vimentin immunohistochemical reactions, can confirm the diagn osis of meningioma. The overall prognosis is good, without a difference in outcome between benign and atypical meningiomas.