[Fibromatosis found during prenatal ultrasonography]

During an antenatal echography, we observed a here to unreported fetal tumour which was diagnosed after birth as aggressive fibromatosis. The infant was treated with chemotherapy and, at the age of 27 months, still had a sclerous mass on the trunk which cause major scoliosis. Fibromatosis is a locally malignant fibrous tumour. During the unpredictable clinical course, recurrence after treatment as well as spontaneous regression is observed. Therapeutic management decisions (surgery, radiotherapy, chemotherapy) must be made on a case by case basis. Hormone factors and inappropriate oncogene expression are pathogenic factor.