Neurofibromatosis type I and intramuscular lesions, pain in left leg. Patient had resection of neurofibromas in the right and left thigh in 2014. On the prior exam, two dominant circumscribed intramuscular neurofibromas were identified in the left thigh, the first anteromedially and the second posterolaterally. There has been interval resection of the anteromedial neurofibroma with postsurgical scarring noted within the overlying soft tissues. The posterolateral (biceps femoris) neurofibroma demonstrates bright T2 signal with a targetoid appearance and measures 1.0 x 1.6 x 3.1 cm (AP x TV x CC), previously 1.9 x 1.5 x 3.2 cm. Additional numerous cutaneous and subcutaneous neurofibromas seen in the left thigh are similar to prior exam. No muscle edema or fatty atrophy. Bone marrow signal of the left femur is within normal limits.On the large field-of-view images, there is a diffuse neurofibroma along the posterior medial aspect of the right thigh. Focal neurofibromas are seen along and within the medial musculature of the right thigh as well as along the posterior right acetabulum. Additionally, multiple cutaneous and subcutaneous neurofibromas are seen, similar in distribution to the prior exam. Also redemonstrated is deformity the distal femur presumably due to a combination of mesenchymal dysplasia and prior surgery.
1. No change in size of the biceps femoris neurofibroma in the posterolateral left thigh. 2. Interval resection of the neurofibroma previously identified in the left thigh anteromedial musculature.3. Additional features of neurofibromatosis as described.