Benign Peripheral Nerve Sheath Tumor of the Skin and Subcutis

Benign Peripheral Nerve Sheath Tumor of the Skin and Subcutis
(NEUROFIBROMA, SCHWANNOMA)

A well-circumscribed dermal or subcutaneous tumor composed of wavy spindle cells arranged in bundles, palisades, and whorls, arising from Schwann cells, perineural fibroblasts, or both.

Gross Appearance:
•Solitary
•Range in size from 0.5-1.0 cm in diameter
•Most are located within the dermis

Histology:
•Low cellularity
•Spindle or polygonal cells loosely distributed in a fibrillar or mucinous matrix
•Nuclei are small and normochromatic

Neurilemmoma (Schwannoma)
•Composed of spindle cells
•Often have S-shaped nuclei
•Cells lie within a loose collagenous stroma

Neurofibroma
•Formation of a nerve fascicle-like structure and associated connective tissue stroma giving the morphologic appearance of peripheral nerve sheaths

Sex Distribution (N=67)

Sex Status
Percent

Male
(46.4%)

47.8%

intact
(13.9%)

10.5

neutered
(32.5%)

37.3

Female
(53.6%)

52.2%

intact
(18.4%)

20.9

neutered
(35.2%)

31.3

(normal sex distribution)

Anatomic Location (N=62)

Site
Percent

Head 51.6

Hindlimb 12.9

Forelimb 11.3

Neck 8.1

Back 8.1

Tail 3.2

Abdomen 1.6

Thorax 1.6

Multiple 1.6