Multiple brain metastases from adenoid cystic carcinoma of the parotid gland. Case report and review of the literature.

BACKGROUND: Adenoid cystic carcinoma is a slow-growing malignant tumor occurring in the head and neck. Intracranial involvement usually results from direct skull invasion from adjacent primary sites. To our knowledge, this is the first reported case of multiple brain parenchymal metastases manifesting with hemorrhage. CASE DESCRIPTION: A 60-year-old male experienced sudden onset of hemiparesis caused by an intracerebral hematoma in a brain metastasis from adenoid cystic carcinoma. The primary parotid tumor was treated 15 months before the appearance of the brain metastases. The hemorrhagic metastasis was resected, and cranial irradiation was performed. The brain metastasis had increased cellular atypism compared with the primary tumor. The patient remained well and free of neurologic dysfunctions until 5 months after the radiotherapy was completed; he died of systemically advanced disease 8 months after the craniotomy.
CONCLUSION: Hematogeneous brain metastases of adenoid cystic carcinoma are quite rare and cannot be distinguished from those of other cancers radiologically. We assume that the intratumoral hemorrhage is related to the tendency of the tumor to spread around the vessels. Although radiation therapy is not curative, it is beneficial in controlling tumor regrowth.