Invasion of cranial nerves by salivary cylindroma: four cases treated by radiotherapy.

Four cases of adenoid cystic carcinoma (cylindroma) of accessory salivary tissue are described, and the diagnostic difficulties experienced are emphasized. The tumour infiltrates cranial and other nerves and may invade the central nervous system by this route. It is highly malignant and may metastasize widely both by haematogenous and lymphatic pathways. The tumour is radiosensitive and it is suggested that the treatment of choice is radiotherapy combined, when possible, with surgical excision of the primary lesion. Metastases should be treated with radiotherapy since useful remission may occur.