[Solitary fibrous tumor of the retroperitoneum in pregnancy: case report].

Solitary fibrous tumor (SFT) is a rare, usually benign tumor Most cases occur on the pleura, being less frequent at other serosal sites. We present a case of a large retroperitoneal tumor with no accompanying clinical symptoms, which was detected due to apparent abdominal asymmetry in a 24-year-old woman at 16 weeks of gestation. The MRI scan taken at 20 weeks demonstrated a retroperitoneal mass measuring 25 cm in length. The tumor was surgically removed at 24 weeks of gestation. The final diagnosis was established on the basis of the anatomopathological examination supplemented by immunohistochemical phenotyping.