[Actinomycotic granuloma of the optic chiasma: a case report].

A case of actinomycotic granuloma of the optic chiasma and the optic nerve is reported. A 53-year-old man was admitted to our hospital with headache and vomiting on September 25, 1989. General physical and neurological examination on admission revealed no remarkable findings. CT-scan demonstrated almost normal pictures. On the 17th hospital day, his temperature was 38 degrees C and white blood cell (WBC) count was 12000 cumm. And he presented right abducens palsy. MRI demonstrated no abnormal findings then. After antibiotic therapy of penicillin intravenously for 4 days, his temperature returned to normal and abducens palsy disappeared for two weeks. He was discharged 43 days after admission. But one year after discharge he developed progressive impairment of right visual acuity. He was admitted to our hospital again on January 19, 1991. His neurological examination revealed severe impairment of right visual acuity and bitemporal hemianopsia. WBC count was 5400 and CRP was negative and temperature was 36.2 degrees C. CT-scan and MRI demonstrated a suprasellar enhancing mass lesion. Serum prolactin was 38 ng/ml. A diagnosis of pituitary adenoma was considered and a right frontotemporal craniotomy was performed. At operation, abnormally swelled right optic nerve and chiasma were found and the swelled chiasma only was resected. Histological examination showed an abscess containing necrotic tissues and actinomycotic granules with radiating filaments. The patient was given penicillin intravenously for 37 days and orally for two months. At that time, MRI revealed no abnormal enhancing lesion, and his visual acuity improved gradually. Actinomycosis of the optic nerve and chiasma is very rare.(ABSTRACT TRUNCATED AT 250 WORDS)