Fig 2.

MRI and metabolic features of neurofibromas and malignant peripheral nerve sheath tumors (MPNSTs). (A) Axial (top panel) and coronal (bottom panel) short T1 inversion recovery magnetic resonance imaging of neck and chest plexiform neurofibroma in a female teenager with neurofibromatosis type 1. Neck pain for several months was attributed to stress and a heavy backpack. Development and progressive enlargement of a distinct nodular lesion were found in the neck and upper chest (arrows). In addition, growth of an anterior neck nodular lesion was found (arrowhead). [¹⁸F]fluorodeoxyglucose positron emission tomography at age 18 years demonstrated [¹⁸F]fluorodeoxyglucose avidity of the two nodular lesions. Biopsy of the deep nodular lesion (arrow) at age 18 years confirmed intermediate-grade MPNST. Surgical resection of MPNST and the anterior neck nodular lesion confirmed atypical neurofibroma (ANF). (B) Volume measurements of the deep and anterior neck nodular lesions over time showed parallel lesion growth from ages 13 to 15 years. Accelerated growth of the deep nodular lesion subsequent to this is concerning for malignant transformation.