29-year-old male with history of NF1, known plexiform tumor in the pelvis. Evaluate plexiform neurofibroma. Again seen are innumerable masses of high signal intensity on STIR images, many having a target appearance, within the skin as well as within the subcutaneous and deep soft tissues of the pelvis compatible with nerve sheath tumors and the known history of neurofibromatosis type I. Plexiform neurofibromas involve the lumbar and sacral nerve roots as well as both sciatic nerves, extending beyond the field-of-view of this study. There are also plexiform neurofibromas involving both femoral nerves, slightly prominent on the right. Additional neurofibromas are noted within the pelvis as well as the surrounding musculature but there is no single dominant lesion to suggest malignancy, within the limitations of this noncontrast examination. Previously referenced lesion along the lateral aspect of the right abductor musculature is not included in its entirety on the current study, however is not significantly changed measuring 2.2 x 1.1 cm, previously 2.2 x 1.3 cm (series 301, image 24). Additional previously referenced lesion within the left rectus femoris muscle belly measures 0.8 x 0.8 cm, previously 0.8 x 0.8 cm (series 301, image 20). The bone marrow signal intensity is within normal limits. The hip joints, sacroiliac joints and pubic symphysis are unremarkable.
Findings compatible with neurofibromatosis with plexiform neurofibromas overall stable in size. 