De novo cystic brain lesions mimicking neurocysticercosis in ALK-positive lung cancer.

Cystic brain metastases (CBM) have been recently reported in a minority of patients with anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC). All previously reported ALK-positive CBM developed during crizotinib treatment and were often asymptomatic and indolent, even without CNS-directed therapy. Thus, crizotinib was suggested as an etiologic agent for the development of CBM. Here, we report a case of de novo CBM in a patient with ALK-positive NSCLC prior to crizotinib treatment; the ALK-positive NSCLC had initially been misdiagnosed as neurocysticercosis because of the atypical radiological presentation of brain metastases.