Adult Still's disease as a paraneoplastic manifestation of breast cancer.

We treated a patient who developed symptoms and findings indistinguishable from those of adult Still's disease as a manifestation of metastatic breast cancer 7 years after treatment for a stage 1 tumor. Although clinical features fulfilled diagnostic criteria for adult Still's disease, examination of a bone marrow biopsy specimen indicated that the apparent adult Still's disease was a paraneoplastic manifestation associated with diffuse marrow infiltration by breast cancer. The fever and polyarthralgia resolved with administration of prednisolone, and antiestrogen therapy with tamoxifen citrate was also started.