Cystic brain necrosis and temporal bone osteoradionecrosis after radiotherapy and surgery in a patient of ear carcinoma.

Brain cyst formation of temporal lobe induced by radionecrosis in ear carcinoma is rare. A 73-year-old man with basosquamous carcinoma of the left external ear canal received excision of tumor and postoperative radiation therapy in 1992. For osteonecrosis of the left temporal bone, a series treatment including oral and intravenous antibiotics and hyperbaric oxygen therapy was given in following years. Encephalomalasia of the left temporal lobe on brain computed tomography (CT) was noted in 1997. The patient suffered from headache, poor concentration, memory impairment, depressed mood, bad temper, and one 8 x 5 x 3.5 cm cystic lesion of the left temporal lobe with tempomandibular joint defect revealed by brain CT in 2001. Symptoms relieved after stereotactic aspiration of cystic fluid and external drainage (Omaya reservoir) insertion under magnetic resonance image by neurosurgeon. We report the progressive radionecrosis of temporal lobe and cyst formation, which caused the neuropsychological symptoms 10 years after radiotherapy.