Prolonged partial remission of malignant fibrous histiocytoma in posterior mediastinum by immunotherapy.

The case of a 16-year-old female patient with the giant cell type of malignant fibrous histiocytoma (MFH) in the left posterior mediastinum is reported. This is a very unusual site for MFH. Immunotherapy induced a prolonged partial remission lasting 15 months with a marked reduction in tumor size. The usefulness of immunotherapy for MFH needs to be evaluated.