[Diagnosis and therapy of fibromatosis in head and neck region (author's transl)].

Fibromatosis is a heterogenous group of soft tissue neoplasias, only some forms of which occur in the head and neck region. In the pathological classification it takes place between the fibroma and fibrosarcoma. With nodular fasciitis, it's subspecies myositis proliferans and aggressive fibromatosis exist differential diagnostic difficulties, especially as it's difficult to exclude fibrosarcoma. The benign myositis proliferans gives an impression of a malignant process by it's rapid proliferation, cell-polymorphia and high mitotic activity. The monomorphous histological picture and the slower proliferation of the aggressive fibromatosis, however can simulate a benign tumor, although thought to be semimalignant. 3-case-reports point out these characteristics. Complete excision is the therapy advised for all fibromatosis. In aggressive fibromatosis a large enough healthy area is the best condition to prevent recidives.