Prenatal diagnosis of a fibrosarcoma of the thigh: a case report.

We report a rare case of fibrosarcoma of the thigh suspected prenatally. At 27 weeks of gestation a voluminous, vascularised mass was discovered at ultrasound on the foetus' left leg, suggestive of haemangioma or a fibrosarcoma. There were no signs of heart failure. A rapid increase in the tumour mass was noted and a caesarean section was carried out at 39 weeks because of abnormal foetal heart rate. Postnatal ultrasound examination was comparable to that carried out prenatally; pathological examination of the mass biopsied and immunohistochemical investigation provided a diagnosis of congenital fibrosarcoma. After neoadjuvant chemotherapy and surgery the infant is now in complete remission without amputation.