Table 2.

Characteristics of Neurofibroma Subtypes Defined by the WHO

Subtype	Location	Relation to NF1	Malignant Potential	Comments
Localized cutaneous	Skin (dermis and subcutaneous)	10% NF1-associated, 90% sporadic	None	Most common subtype. In NF1, may be overlain by café-au-lait macules
Diffuse cutaneous	Skin (dermis and subcutaneous)	10% NF1-associated, 90% sporadic	Very low, but does occur	Uncommon lesions that present as plaque-like thickenings of skin
Localized intraneural	Cranial, spinal or autonomic nerves	Can be either sporadic or NF1-associated	Intermediate	Second most common subtype
Plexiform	Cranial, spinal or autonomic nerve plexuses	Exclusively NF1-associated	Highest	Key diagnostic for NF1
Massive soft tissue	Extremities, extensive soft tissue expansion with underlying large nerve	Exclusively NF1-associated	Intermediate, but low clinical impact due to rarity	Least common subtype, also known as elephantiasis neuromatosa