Neurofibromatosis, arm mass Within the medial soft tissues of the arm is a well-circumscribed mass measuring 4.3 x 4.6 x 7.3 cm in the greatest transverse, AP, and craniocaudal dimensions. The mass is predominantly hyperintense to skeletal muscle on T2-weighted sequences (although contains some areas of heterogeneous low signal intensity) and isointense to skeletal muscle on T1 sequences. The mass does not appear to invade the surrounding fat planes and is and otherwise does not demonstrate aggressive features. Following contrast administration, there is solid but heterogeneous enhancement. This mass was evident on the comparison examination from 2011 and has increased from that exam when it measured approximately 3.9 x 4.3 x 6.5 cm.A second similar appearing mass is identified just posterior to the humerus at the same level. This mass measures approximately 1.7 x 1.6 x 3.2 cm in the greatest transverse, AP, and craniocaudal dimensions. Following contrast administration, there is solid central enhancement. This mass was evident on the comparison examination from 2011 and has increased from that exam when it measured 1.3 x 1.2 x 2.5 cm.A third smaller mass is seen within the anterior soft tissues and is further detailed on the dedicated MRI of the left elbow.The underlying marrow signal of the humerus is normal.
Multiple soft tissue masses consistent with peripheral nerve sheath tumors. These have increased in size from a comparison exam of the left humerus dated 4/20/2011.