[Surgically treated syphilitic gumma of the brain. Computerized tomography findings].

Syphilitic gumma is now exceptional. Symptomatology is non-specific and frequently, as in the case reported here, the onset is marked by a localized or generalized convulsion. A space-occupying lesion is recognized by angiography and CT. The precise diagnosis is suggested by evidence of arteritis or of a hypodense mass outlined by contrast or slight calcifications and confirmed by positive serology in a patient with a suspected cerebral tumor. In some cases a positive diagnosis can be made only by pathological examination after surgical ablation of the gumma. An area of central necrosis is surrounded by a granulomatous layer rich in plasmocytes (the polyclonal nature of the secretion is shown by immunocytochemistry) and a peripheral fibroblastic zone. The arteries are ensheathed by a dense inflammatory infiltrate constituted almost entirely by plasmocytes and their lumens are either stenosed or filled with endarteritic debris. Surgical treatment should be combined with penicillin administration. For a patient in good general condition with a suspected gumma, medical treatment can be given initially, with follow-up by CT, neurosurgery being indicated only in case of failure of medical therapy. The rarity of gummata in relation to other tertiary syphilitic lesions remains unexplained. The patient reported here had multiple infections including one due to cytomegalovirus after ablation of the gumma, highly suggesting an immunity disorder.