31 year old male with a history of NF1 and plexiform behind the right knee but extensive tumor beyond. ARTICULAR CARTILAGE AND BONE: No bone marrow signal abnormalities identified.SOFT TISSUES: Note is made of an extensive plexiform appearing masses within the soft tissues about the posterior aspect of the right knee extending inferiorly along the anterior and lateral aspect of the calf as well as along the posterior aspect of the distal femur with associated T2 prolongation peripherally with central low intensity, consistent with the patient's history of neurofibromatosis, although these are incompletely characterized due to the lack of intravenous contrast. The largest lesion along the lateral aspect of the popliteal fossa measures approximately 8.3 x 5.0 cm (image 97; series 1701) and demonstrates heterogeneous internal signal intensity, previously measuring 7.4 x 4.7 cm. Further characterization of these lesions is limited due to the lack of intravenous contrast and dedifferentiation cannot be excluded by this examination. Additional foci of intramuscular fluid signal intensity are identified within the adductors, hamstring, sartorius and quadriceps musculature of the right thigh which appear most consistent with neurofibromas. Additional masses are identified within the left thigh musculature which are also most consistent with neurofibromas. Additional foci of fluid signal intensity are identified within the incompletely imaged pelvis which also may represent neurofibromas, incompletely characterized. There are also multiple foci of increased signal intensity on fluid sensitive sequences within the subcutaneous tissue about the anterior and lateral aspect of the calf and anterior aspect of the thigh which may represent cutaneous neurofibromas.There is mild to moderate muscle atrophy.The severe atrophy of the tibialis posterior, flexor digitorum longus musculature.ADDITIONAL
Findings consistent with the patient's history of neurofibromatosis with associated large plexiform neurofibroma along the posterior aspect of the knee. There is interval increase in size of a 8.3 cm lesion along the lateral aspect of the popliteal fossa, which is incompletely characterized on this noncontrast examination, as described above. 