Fig. 2.

Magnetic resonance imaging of the left forearm demonstrating a peripheral nerve sheath tumor with atypical features suggestive of malignancy. (A) Axial T1-weighted image showing a lobulated soft-tissue mass in the anteroulnar compartment of the proximal forearm (white arrow), closely related to the ulnar nerve. (B) Axial fat-suppressed postgadolinium T1-weighted image demonstrating avid heterogeneous enhancement and marked hypervascular appearance of the lesion (white arrow). (C) Coronal T2-weighted image showing longitudinal extension of the mass along the flexor compartment, apparent involvement of adjacent flexor muscles, and a pseudo-infiltrative appearance (white arrow), without osseous involvement.