Meningeal carcinomatosis preceded by a rapid increase in serum CA19-9 levels in a patient with breast cancer.

We report a patient with breast cancer who developed meningeal carcinomatosis that was preceded by a rapid increase in the serum level of carbohydrate antigen (CA) 19-9. A 60-year-old woman was admitted for primary breast cancer with multiple metastases to the vertebrae. She received cyclophosphamide 400 mg/m(2), epirubicin 40 mg/m(2), and 5-fluorouracil (5-FU) 400 mg/m(2) (CEF) chemotherapy every 3 weeks. Upon admission, her serum concentrations of carcinoembryonic antigen (CEA) and CA19-9 were 28.6 ng/ml and 99.2 U/ml, respectively. After three cycles of CEF therapy, her serum CEA decreased, and metastases to the vertebrae were attenuated. Her serum CA19-9 rapidly increased, however. A modified radical mastectomy was performed, but her serum CA19-9 levels still remained high (>500 U/ml). After four cycles of CEF therapy, she experienced headaches and vomiting due to an increase in cerebrospinal pressure, and she was diagnosed with meningeal carcinomatosis. At the time of this diagnosis, the concentration of CA19-9 in her cerebrospinal fluid was greater than 500 U/ml, and immunohistochemical examination revealed that carcinoma cells in the cerebrospinal fluid overexpressed CA19-9. To our knowledge, this is the first report of the development of meningeal carcinomatosis from CA19-9-producing breast cancer cells, showing thatCA19-9 expression was associated with breast tumor progression.