A Unique Case of a Patient With Pancreatic Cancer Developing Leptomeningeal Metastases While on Gemcitabine and Nab-Paclitaxel.

Brain metastases and leptomeningeal disease are rare with pancreatic cancer. Leptomeningeal disease is a catastrophic complication to have as patients deteriorate rapidly. Patients can present with symptoms of cranial nerve neuropathies, headache, nausea, and focal neurological deficits. We present a patient with metastatic pancreatic cancer who was treated initially with FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) which resulted in marked clinical and radiologic improvement. However, he started to develop severe peripheral neuropathy and was switched to maintenance gemcitabine and nab-paclitaxel. On this regimen, his systemic disease was well controlled but he developed leptomeningeal carcinomatosis. To our knowledge, this is the first case of leptomeningeal metastases developing in a patient with pancreatic adenocarcinoma while on treatment with gemcitabine and nab-paclitaxel after cessation of FOLFIRINOX. We should maintain high clinical suspicion for leptomeningeal disease in pancreatic cancer, especially when systemic disease is well controlled, as the chemotherapeutic agents may not be crossing the blood-brain barrier effectively contributing to high morbidity and mortality.