Acoustic neurinoma and posterior fossa meningioma. Clinical and CT radiologic findings.

Clinical and computed tomography (CT) findings of twenty-three patients with acoustic neurinoma (AN) and eleven patients with posterior fossa meningioma (PFM) are described. AN frequently (94%) presents with the complaint of hearing loss, while PFM often (60%) presents with non-specific pains in the head or neck. The CT characteristics of AN and PFM in this series were similar to those found in most previous publications. The maximal measured mean diameter of PFM (40.2 mm) was significantly larger than that of AN (26.4 mm). Hydrocephalus was apparently influenced by tumor location rather than by its size. It is concluded that diagnostic ability has been improved in cases of CPA tumors, but not in those of non-CPA PFM, probably because of the earlier clinical presentation of the former. Clinical efforts are still necessary to detect the smaller tumors.