Perineural lipomatosis (Q90766)

Perineural lipomatosis (lipomatosis of nerve) is a rare condition in which the epineurial and perineurial compartments of the affected nerve are infiltrated by mature adipose tissue admixed with fibrous tissue which dissects between and separates individual nerve bundles. It is frequently first noted at birth or in early childhood, but affected individuals may not present for treatment until adulthood. In some cases it is associated with macrodactyly of the digits innervated by the affected nerve. The median nerve and its digital branches are the most commonly nerves though it may also affect the ulnar nerve.