For many years, pathologists have sought to create some order in the classification of non-metastasizing fibrous tissue disorders ranging from the benign keloid at one end of the scale to the "non-metastasizing fibrosarcoma" at the other. It is now generally accepted that these fibrous anomalies are members of the same family and the entire range from the most benign to the most bizarre is encompassed by the term "fibromatosis". Unfortunately, some of these lesions behave in a most aggressive manner and there appears to be little correlation between the histological appearance of the tumor and its clinical aggression. Some, particularly if occurring in the head and neck may pursue a relentless course and, defying all forms of therapy, result in death of the patient. Recently a young man presented with fibromatosis in the supraclavicular region. Despite a short history, the lesion was quite advanced and was considered surgically unresectable. Radiotherapy was thus considered to be the treatment of choice.