Frequency of pseudotumoral CNS lesions in an oncology center

Abstract Background Brain tumors are frequent in clinical practice and associated with high morbidity and mortality. However, many diseases can present as tumefactive lesions and mimic neoplastic lesions. We aimed to determine the frequency of pseudotumoral CNS lesions referred to an Oncology center and the frequency of the tumor mimickers. Methods Retrospective study at the National Institute of Cancer, Rio de Janeiro, Brazil. Medical charts of patients admitted to the Neurosurgery and Pediatrics services from 2007 to 2011 were reviewed. Clinical and radiological features of cases initially diagnosed with primary CNS tumors but received a final diagnosis of pseudotumoral disease were recorded. Results Among 891 patients referred as primary brain tumors, 38 cases had pseudotumoral lesions (4.3%). Most were adults (63%), with mean age of 29.4 years, and women (60.5%). Most frequent symptoms were headache (28.9%), motor signs (23.7%) and seizures (15.8%). Mean time from initial symptoms to diagnosis was 12.2 months. Lesions were single in 84.2% of patients, had contrast enhancement in 45.6% and surrounding edema in 17.4%. Twenty patients (52,6%) underwent biopsy. Systemic autoimmune diseases were the most frequent etiologies (28.9%), followed by idiopathic inflammatory demyelinating diseases, infections and vascular abnormalities (15.8% each). Good outcome with no major deficits was observed in 60.5% cases. Conclusions The frequency of pseudotumoral lesions in an oncology reference center was low. Young women were most affected, and lesions were associated more frequently to systemic autoimmune diseases. Prompt recognition is important to avoid unnecessary treatment since most patients had a good outcome.