Neural Fibrolipoma
Definition
- Benign, localized expansion of epineurial adipose and fibrous tissue
Alternate/Historical Names
- Fibrolipomatosis of nerve
- Fibrolipomatous hamartoma of nerve
- Lipofibroma of nerve
- Lipomatosis of nerve
- Neural lipofibromatous hamartoma
- Neurolipomatosis
Diagnostic Criteria
- Surrounds and infiltrates a segment of a major nerve
- Sausage shaped expansion
- Most often involves upper extremity and median nerve
- Rare cases involve ankle/foot
- Mature adipose tissue with a fibrous component
- Epineurium expanded by adipose tissue
- Marked, concentric perineurial thickening
- EMA and CD34 positive
- Separates nerve bundles
- Metaplastic bone has been reported
- Affected nerve may show pseduo-‘onion-bulb’ like change (can be confused with intraneural perineurioma)
- May have associated bone overgrowth causing macrodactyly
- No association with neurofibromatosis
- Usually under age 30
- Usually presents with sensorimotor deficits
- Benign but may require excision or release of compression
Jason Karamchandani MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting: 11/17/10
