Cerebral syphilitic gumma mimicking malignant brain tumor in a human immunodeficiency virus-negative patient

Cerebral syphilitic gumma is considered an uncommon involvement of the brain during tertiary syphilis and the differentiation from a brain mass in HIV-negative patients with syphilis is still challengeable to clinicians. We report an unusual case of cerebral syphilitic gumma mimicking malignant brain tumor in a human immunodeficiency virus-negative patient. A 41-year old man complaining of headache was found to have a brain mass on his CT scans and MRI. A rapid plasma reagin screening and the treponema pallidum hemagglutination assay was reactive in serum but Venereal Disease Research Laboratory results were negative in cerebrospinal fluid. Suspecting a brain tumor, the mass was completely surgically resected through supraorbital keyhole approach. The pathological examination demonstrated a syphilitic gumma. water-soluble penicillin G was intravenously administered for 10 days from postoperative day. 2 weeks and Three months postoperatively, the follow-up MRI scans showed that the enhancing mass in the right frontal region had disappeared; edema around the enhancing mass had also disappeared.