Leptomeningeal carcinomatosis presenting as catatonia

Lung cancer is a common cause of cancer deaths worldwide. Cancer molecular profiling of somatic mutations in lung cancer helps both predict the underlying biology and identify therapeutic targets. c-ROS proto-oncogene 1 receptor tyrosine kinase (ROS1) rearranged lung cancer is a rare molecular subtype of lung cancer that is associated with central nervous system metastases and amenable to targeted therapy. We present a case of a patient with metastatic non-small cell lung cancer with a ROS1 rearrangement who acutely presented with catatonia while on targeted treatment. A full diagnostic workup revealed that the acute decline was secondary to leptomeningeal carcinomatosis (LMC). This case report describes the diagnostic workup for this atypical presentation of LMC and the subsequent treatment strategies. This case challenges the traditional paradigm that patients admitted with cancer-related decline are not candidates for systemic therapy and highlights the key role of collaboration with the oncology team.