Malignant peripheral nerve sheath tumors. A clinicopathologic study of 120 cases

Abstract

A review was done of 120 cases of malignant peripheral nerve sheath tumor (MPNST) seen during a 71-year period. Of the 120 patients, 52 were males and 68 were females with a mean age at diagnosis of 35.3 years; 12 patients were younger than 20 years. The series included 62 (52%) patients with neurofibromatosis, 13 (11%) with postradiation sarcomas, and 19 (16%) with metaplastic foci. The incidence of MPNST arising in neurofibromatosis was 4.6% in the current series and 0.001% in the general clinic population. Tumors greater than 5 cm and the presence of neurofibromatosis adversely affected the prognosis (P less than 0.05). When both features were present, survival was greatly decreased. Patients with tumor in the extremities did better than those with head or neck lesions. Metaplastic foci or previous radiation at the tumor site did not alter the prognosis. Each tumor was graded 1 to 4 on the basis of cellularity, pleomorphism, mitotic index, and necrosis. No significant correlation was noted between survival and either grade or mitotic rate. Survival was improved when total rather than subtotal resection was done. This was most marked in patients with a small lesion, which may reflect the difficulty in adequately excising large tumors. Adjuvant radiation or chemotherapy did not appear to affect survival. The MPNST is an aggressive uncommon neoplasm, and large tumor size, the presence of neurofibromatosis, and total resection are the most important prognostic indicators.

Orthopaedic Case of the Month: A 14-Year-Old Boy With a Medial Thigh Soft Tissue Mass

“…Approximately 1 . 2 of patients with malignant peripheral nerve sheath tumors have neurofibromatosis, Type I (NF-1) [16,17,27,46,51]; however, the cumulative risk of having malignant peripheral nerve sheath tumors develop among patients with NF-1 varies from 2% to 29% [17,34,47]. On immunohistochemistry, S-100 positivity frequently is seen [13,34].…”

Retroperitoneal Peripheral Nerve Sheath Tumour of Triton Type—A Case Report

“…MPNSTs are known to arise from major and minor peripheral nerves or within pre-existing neurofibromas, and approximately 50% of patients with MPNSTs have NF-1 [1,2]. NF-1 is an autosomal dominant disorder characterized by café-au-lait spots, cutaneous neurofibromas, skeletal dysplasias, Lisch nodules, and sometimes malignant tumours.…”

“…The precise cell of origin of MPNSTs has not yet been conclusively identified, although the Schwann cell is thought to be the major candidate cell. The capacity of MPNSTs to undergo focal divergent differentiation is well known, and tumours showing rhabdomyosarcomatous differentiation, referred to as MTTs, are identified in approximately 12% of patients with MPNSTs [1]. Woodruff et al [3] reported a series of ten cases of malignant schwannoma with rhabdomyoblastic differentiation, which they were the first to refer to as MTTs.…”

Borderline- und maligne mesenchymale Tumoren des Abdomens

“…Das errechnete "lifetime risk" für eine maligne Entartung beträgt etwa 5-13 % [5,6] und geht mit einer schlechten Prognose und einem 5-Jahres-Überleben von etwa 42 % einher [18,21]. Dies ist auf die einerseits späte Detektion und die frühe Metastasierungstendenz primär in die Leber, Lunge, Lymphknoten, Gehirn und Knochen erklärbar [19] sowohl die Ausdehnung und das Grö-ßenwachstum, das kompressionsbedingt zur entsprechenden Symptomatik führen kann, als auch morphologische Verän-derungen und im Fall der malignen Transformation ein deutlich erhöhter Glukosestoffwechsel nachgewiesen werden (.…”