The central nervous system as a sanctuary site in ALK-positive non-small-cell lung cancer.

Anaplastic lymphoma kinase (ALK) gene rearrangements define a distinct molecular subset of non-small-cell lung cancer that is highly responsive to treatment with the ALK inhibitor crizotinib. Recently, it has been recognized that the brain is a frequent site of relapse among ALK-positive patients treated with crizotinib. In this report, we expand on these observations and present a series of ALK-positive patients with two distinct forms of metastatic, central nervous system involvement: intramedullary spinal cord metastasis and leptomeningeal carcinomatosis.