Q. What is the difference between a neurofibroma and a neuroma?

A. A neuroma is a general term that applies to any of a number of different things (neoplastic or non-neoplastic) that make a nerve or nerve bundle swell. Usually, another word is attached to give more specific meaning.

Neoplastic neuromas are tumors of any part of a nerve (including the surrounding myelin); sometimes the term is used more broadly to refer to any tumor of neural tissue. An example of a neoplastic neuroma is acoustic neuroma, a benign tumor surrounding the 8th cranial nerve (you can also call this tumor a schwannoma, since it is a neoplasm derived from the Schwann cells surrounding the nerve, not the nerve itself).

The main non-neoplastic neuromas are traumatic neuroma (a non-neoplastic reaction of a nerve to some sort of damage) and Morton’s neuroma (which is not even a neuroma, but just an accumulation of fibrous tissue around a nerve, usually in the foot).

Neurofibromas are benign neoplasms derived from the myelin sheath of peripheral nerves (just as a reminder: the myelin surrounding peripheral nerves is supplied by Schwann cells; the myelin surrounding central nerves is supplied by oligodendrocytes). They often occur in the context of neurofibromatosis, a hereditary condition characterized by multiple cutaneous neurofibromas, pigmented skin lesions, skeletal abnormalities, macrocephaly, epilepsy, and a bunch of other findings. In the photo above, the patient has multiple neurofibromas scattered over his entire body.

Neurofibromas are like schwannomas, in that they are derived from schwann cells. However, a schwannoma has mostly just schwann cells in it, whereas a neurofibroma has a bunch of other cell types, like fibroblasts, endothelial cells, and mast cells.