CT and MRI manifestations of plexiform neurofibromas in the head and neck

Objective: To assess the CT and MRI features of plexiform neurofibromas (PNF) in the head and neck. Methods: CT (6) and MRI (10) of 15 patients with pathologically proven PNF in the head and neck were analyzed retrospectively. Results: Of 17 PNF, 7 were located in the scalp (5) skin and subcutaneous tissue (2), and 10 invaded deep soft tissues of the maxillofacial region. The superficial PNF had uniform CT density similar to that of muscle, uniform T₁ isointensity and slight T₂ hyperintensity with some fat signal intensities and small vessels within the lesions showing moderate enhancement. The 10 invasive PNF had beaded or stripe shapes, heterogeneous CT attenuation slightly lower than that of muscle, T₁ isointensity, mixed T₂ hypo- and hyperintensities with target appearance in some. Enhancement was mild on CT, mild-moderate on MRI. Conclusion: Superficial and invasive PNF in the head and neck have characteristic CT and MRI features. (authors)