Prenatal management of congenital infantile fibrosarcoma: unexpected outcome

We report the case of a large leg tumor in a fetus at 36 weeks of gestation. The tumor's location, ultrasound characteristics and magnetic resonance imaging (MRI) findings enabled a prenatal diagnosis of congenital fibrosarcoma and allowed us to establish the prognosis. After multidisciplinary discussion, it was decided that the pregnancy should continue to 38 weeks, with surgery or neo-adjuvant chemotherapy scheduled after delivery. Unfortunately, the tumor unexpectedly burst in utero and the newborn died of the consequences of hemorrhagic shock, despite rapid amputation. Histological examination confirmed the nature of the tumor. The prognosis of congenital fibrosarcoma is generally good when there are no metastases. MRI is key to establishing a prenatal diagnosis. However, rupture of the tumor can result in fatal hemorrhaging and the pregnancy should be monitored closely before scheduled delivery.