Tumor-like Presentation of Primary Angiitis of the Central Nervous System. Report of Two Cases

Primary angiitis of the central nervous system (PACNS) is a rare condition of unknown etiology affecting the central nervous system (CNS) in the absence of systemic vasculitis, inflammatory or infectious disease [1,2]. Initially described in 1959 by Cravioto & Feigin [3], this condition has been increasingly reported in the literature. It is characterized by nonspecific granulomatous or nongranulomatous inflammation of small and/or medium caliber cerebral, leptomeningeal, and/or spinal cord arteries and veins [3]. Clinical presentations are often nonspecific, with diagnosis based on clinical, laboratory, imaging and pathological findings4. It generally occurs in young-adults (30-60 years old) without vascular risk factors, with a mean age of presentation of 45.5 years. The most common manifestations are headaches, focal neurologic symptoms, seizures, cognitive impairment, and psychiatric changes [1]. It has an estimated incidence of 1-2.4 per million per year in European populations [2-5]. The tumormimicking form is rare, accountry for 5 to 15% of all cases of PACNS [5-7]. Tumor-mimicking PACNS often carries worse outcomes than the typical forms [8]. Diagnosis of PACNS represents a difficult challenge for clinicians due to the lack of clinical, serological, and neuroradiological specific hallmarks. Diagnostic criteria for PACNS were proposed in 1988 by Calabrese & Mallek [1]. These criteria have been used widely for clinical and investigation purpose. Patients should meet all of the following criteria to be diagnosed with PACNS: