Malignant Peripheral Nerve Sheath Tumor of the Skin and Subcutis

Malignant Peripheral Nerve Sheath Tumor of the Skin and Subcutis
(NEUROFIBROSARCOMA, MALIGNANT SCHWANNOMA)

An infiltrative spindle cell tumor thought to arise from Schwann cells, perineural fibroblasts, or both.

Gross Appearance:
•Tumor resembles a fibrosarcoma

Histology:
•Tumor cells resemble that seen in neurofibromas with differentiation to peripheral nerve sheath fascicles
•Increased pleomorphism and hyperchromatism
•Mitotic figures may be found

Sex Distribution (N=)

Sex

Status

Percent

Male	(46.4%)
53.6%

intact

(13.9%)

17.7

neutered

(32.5%)

35.9

Female	(53.6%)
46.4%

intact

(18.4%)

16.7

neutered

(35.2%)

29.7

(normal sex distribution)

Anatomic Location (N=246)

Site
Percent

Head 34.1

Forelimb 20.3

Hindlimb 19.5

Neck 9.3

Thorax 5.3

Tail 4.1

Abdomen 3.3

Back 2.8

Perineum 1.2