[A Case of Granulocyte-Colony Stimulating Factor Producing Breast Cancer That Caused Rapid Progression].

We report a case of granulocyte-colony stimulating factor(G-CSF)producing breast cancer in a 54-year-old woman. Eight months after surgery, multiple liver and pulmonary metastases appeared. They progressed rapidly in 2 weeks and she had a high fever of 38 degrees. Serum G-CSF was high, and positive cells were found by immunostaining of the primary tumor. Chemotherapy was initially successful but she died 4 months after relapse.