18-year-old male with Bannayan-Riley-Ruvalcaba syndrome and arteriovenous malformation involving his pelvis, left buttock, and left lower extremityEXAMINATION: MRI left femur and MRI pelvis without and with intravenous contrast 12/9/2016 A mass in the left piriformis is present and not significantly changed measuring 7.3 x 5.4 cm (series 7, image 20). The mass demonstrates heterogeneous T2 signal with internal areas of high T1 signal intensity, suggestive of fat, and minimal enhancement. Internal tubular serpiginous structures are present compatible with dilated blood vessels. There is similar mass effect on the left posterolateral wall of the rectum.A mass in the left semimembranosus/semitendinosus muscles is present, also not significantly changed measuring 6.4 cm x 5.5 cm (series 26, image 33). Similarly to the piriformis lesion, the mass is mildly enhancing and contains dilated blood vessels as well as heterogeneous T2 signal with internal areas of high T1 signal intensity.Ectatic tubular structures are present within the soft tissues of the left lower extremity similar to prior compatible with dilated veins.No new sites of disease.Bone marrow signal intensity is normal.
Unchanged vascular malformations in the left piriformis and left semimembranosus/semitendinosus muscles. The lesions demonstrate MRI features suggestive of fibro-adipose vascular anomalies (FAVA). 