School ager with a rapidly enlarging soft tissue mass of the right chest and arm

CXR and CT of malignant peripheral nerve sheath tumor in neurofibromatosis type 1 — CXR PA and lateral shows a right apical thoracic mass with associated rib thinning that had rapidly increased in size in a short interval. Axial CT without contrast of the chest better defined the right apical mass and demonstrated multiple serpiginous nodules in the soft tissues of the right anterior chest wall.

The diagnosis was degeneration of a plexiform neurofibroma into a malignant peripheral nerve sheath tumor in a patient with neurofibromatosis type 1.