Cranial invasion by basal cell carcinoma.

The direct spread of basal cell carcinoma (BCC) into the bones of the cranium takes a long period. In its early stages, it may not be detectable by radiography or computerized tomography, but can be visible as pitting during surgery. Invasion through the thickness of the calvarium due to extension of a BCC of the scalp, or involvement of the cribriform plate by spread from an intranasal lesion, is serious. Examples of cranial invasion by BCC are presented. The methods used in diagnosis and treatment are outlined.