Diffuse neurofibroma (DF) is an uncommon variant that is usually seen in the setting of Neurofibromatosis 1 but may also rarely occur sporadically. It frequently involves the head and neck region in children and young adults. The tumor is poorly-circumscribed and spreads laterally along tissue planes causing plaque-like thickening of the skin. Grossly, it appears as firm yellow-gray mass in the subcutaneous tissues (as shown here). It surrounds but does not destroy normal structures in its path. Image courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.com; Used with permission.