A Rare Case of Simultaneous Brain and Leptomeningeal Metastases in a Patient With Pancreatic Cancer.

Pancreatic cancer rarely metastasizes to the brain or meninges. Here, we describe a case in which a patient developed both. Our patient, a 75-year-old male individual, was diagnosed with pancreatic tumor on computed tomography (CT) of the abdomen and pelvis after presenting for abdominal pain. The patient underwent an endoscopic ultrasound-guided fine needle aspiration of the pancreatic mass and pathology was consistent with adenocarcinoma of the pancreas. A positron emission tomography (PET) scan showed metabolically active pancreatic head mass, retroperitoneal soft tissue nodule/lymph node, soft tissue thickening adjacent to the celiac artery, and within the anterior left lung hilum. He was treated with neoadjuvant chemotherapy followed by Whipple procedure due to presence of oligometastasis with great response to initial treatment. He later developed a frontal headache while on surveillance. MRI of the brain demonstrated multiple intraparenchymal metastases as well as leptomeningeal carcinomatosis. The patient underwent a posterior fossa craniotomy for resection of the mass. The pathology was consistent with metastatic pancreatic adenocarcinoma. This case describes a malignancy that presented with a unique form of metastasis.