Solitary Circumscribed Neuroma
Differential Diagnosis
| Solitary Circumscribed (Palisaded Encapsulated) Neuroma |
Schwannoma |
| 90% of lesions affect the face |
Can occur anywhere |
| Common in the dermis |
Uncommon in the dermis |
| Peripheral, delicate EMA positivity |
Completely surrounded by perineurial capsule |
| GFAP negative |
Can be GFAP positive |
| Axons throughout the lesion |
Axons, when present, are typically peripheral / subcapsular |
| No organization into Antoni A and Antoni B areas |
Feature Antoni A and Antoni B areas |
| Solitary Circumscribed (Palisaded Encapsulated) Neuroma |
Neurofibroma |
| 90% of lesions affect the face |
Can occur anywhere |
| Usually solitary |
Frequently multiple |
| Delicate EMA peripheral positivity |
No peripheral perineurial capsule |
| GFAP negative |
Can be GFAP positive |
| Rare mast cells |
Frequent mast cells |
| Predominantly composed of Schwann cells |
Contain neural fibroblasts and fibrillary collagen |
| No known familial association |
May be associated with neurofibromatosis |
Both contain axons throughout
| Solitary Circumscribed (Palisaded Encapsulated) Neuroma |
Mucosal Neuroma/Neuromatosis |
| Usually solitary |
Frequently multiple |
| Lacks structure of normal nerves |
Hyperplastic normal nerves |
| Perineurium present at the periphery |
Perineurium present around individual nerve bundles |
| No known familial association |
Associated with MEN2b |
| Traumatic Neuroma |
Solitary Circumscribed (Palisaded Encapsulated) Neuroma |
| Can occur anywhere |
90% of lesions affect the face |
| Usually located in soft tissue |
Usually located in dermis |
| History of trauma or surgery |
No history of prior trauma or surgery |
| Can have irregular margin |
Generally circumscribed |
| Numerous well formed small nerve twigs |
Random proliferation of Schwann cells and axons |
| EMA+ perineurium surrounds individual nerve twigs |
EMA+ perineurium restricted to periphery of the entire neuroma |
