Superficial Malignant Peripheral Nerve Sheath Tumor

Abstract

We reviewed the clinicopathologic features of 5 cases of malignant peripheral nerve sheath tumor (MPNST) manifesting in superficial locations associated with cutaneous neurofibromas (4 cases) or superficial peripheral nerve (1 case). Four cases had spindle cell morphologic features and were at least focally positive for S-100 protein, whereas the associated benign neural elements had more extensive S-100 immunoreactivity. The single epithelioid case was diffusely and strongly positive for S-100 protein. Melanoma markers, epithelial membrane antigen, glial fibrillary acidic protein, neurofilament, pancytokeratin (AE1/AE3), CD34, smooth muscle actin, and desmin were negative in all cases. There were no local recurrences, but 3 patients died of metastatic disease within 2 to 30 months (median, 21 months). MPNSTs can occur in a superficial location and may have an aggressive clinical course. Immunohistochemical markers are helpful in excluding other lesions in the differential diagnosis. However, identification of a benign precursor or origin from a nerve may be the most definitive way to properly classify these rare lesions.

Microsurgical management of giant malignant peripheral nerve sheath tumor of the scalp: two case reports and a literature review

“…It seems that the current treatment of these highly malignant tumors, however, is not that pessimistic. As some authors have pointed out, the survival rates of patients with MPNSTs were significantly better for superficial tumors, such as MPNST of the scalp [5]. Other authors, however, believe that the present data does not allow final conclusions about the prognosis of MPNST of the scalp, because these results are based on a small patient population with primarily short follow-up periods [17].…”

“…A variety of terminologies, including neurofibrosarcoma, neurogenic sarcoma, malignant schwannoma, and malignant neurilemomma have been used to describe the tumor. As defined by the World Health Organization, however, the universal or standard terminology should be malignant peripheral nerve sheath tumor [1-5]. Although the incidence of malignant peripheral nerve sheath tumor of the scalp is very low, it is highly malignant and is associated with poor prognosis [1-3].…”

Selected topics in the pathology of epithelioid soft tissue tumors

“…Most involve major nerves, 54 although rare tumors may occur in unusual locations such as the skin. 55 For unclear reasons, EMPNST accounts for the great majority of MPNST that arises within schwannomas (an exceedingly rare event). 51,56 EMPNSTs are aggressive lesions, with distant metastases eventually occurring in B50% of patients, typically to the lungs.…”

Cutaneous Superficial Malignant Peripheral Nerve Sheath Tumor

“…As some authors have indicated, the survival rates of patients with MPNSTs were significantly better for superficial tumors (11). Positive tumor margins are defined as the most important prognostic marker (12).…”