Neurofibromas may form circumscribed masses in dermis or soft tissue with variable, white-tan appearance (a). When involving a main peripheral nerve trunk, neurofibromas cause fusiform expansion (b). Wavy nuclei and “shredded carrot” type collagen are typical (c). Diffuse neurofibroma, a less common subtype, may form large masses with infiltration of fat and numerous pseudomeissnerian corpuscles (d). S100 usually labels a subset of cells of probable schwannian origin in neurofibromas (e), while CD34 shows variable reactivity, highlighting cells of an uncertain nature (f).