Predictive value of ANCA in atypical primary brain localization of Wegener's granulomatosis.

Wegener's Granulomatosis is a necrotizing vasculitis generally involving upper and lower respiratory tract and kidneys. The central nervous system is involved in less than 10% of the patients during the course of the disease and primary involvement is even rarer. We present and discuss the case of a patient with primitive cerebral localization of Wegener's Granulomatosis in which the diagnosis and the beginning of correct therapy were delayed, in spite of a rising c-ANCA titer, due to a misinterpretation of a bioptic specimen. This delay caused renal damage and pulmonary cavitations which needed a long time to recover. This case report suggests that the central nervous system can be the site of a primary localization of Wegener's Granulomatosis even without any other organ involvement. The diagnosis must be made as soon as possible in order to prevent spread to other sites since the disease is usually very aggressive and severe.