Pancreatic cancer with leptomeningeal carcinomatosis: case report and literature review.

Leptomeningeal carcinomatosis (LMC) associated with pancreatic cancer is an extremely rare complication. Symptoms vary depending on the site of invasion and include intracranial pressure, and cranial and spinal dysfunction making early diagnosis difficult. We describe a rare case of leptomeningeal metastasis from pancreatic cancer. A 59-year-old man was diagnosed with unresectable pancreatic cancer and subsequently received systemic chemotherapy. Initial chemotherapy was effective. After 12 months the patient's serum carbohydrate antigen (CA)19-9 level had become elevated, and he presented with neck and back pain, and shoulder stiffness. Tumor enlargement was not detected by computed tomography (CT) and positron emission tomography-CT. Contrast CT of the brain revealed evidence of leptomeningeal enhancement. Cerebrospinal fluid cytology showed atypical, but not malignant cells; the CA19-9 level was further elevated. The patient was finally diagnosed with LMC and, being in poor general condition, received palliative care. During the treatment of pancreatic cancer, the potential existence of LMC should be contemplated when a serum tumor marker becomes rapidly elevated despite the control of primary or metastatic sites. © The Japan Society of Clinical Oncology 2020.