Patterns of involvement of the temporal bone in metastatic and systemic malignancy

The temporal bone appears to be involved with secondary malignant processes in discrete histologic patterns with rather characteristic clinical presentations. Five distinct types of involvement can be recognized: isolated metastasis from a distant primary tumor; direct extension from a regional primary tumor; meningeal carcinomatosis; leptomenin-geal extension from an intracranial primary tumor; and leukemic or lymphomatous infiltration. The typical histopathological patterns are described with correlative clinical symto-matolgy. Differential diagnosis is considered, and guidelines for surgical management are discussed.