Type:
Educational Exhibit
Keywords:
Pathology, Neoplasia, Motility, Surgery, Contrast agent-intravenous, Biopsy, Ultrasound, MR, CT, Neuroradiology spine, Neuroradiology peripheral nerve, Extremities
Authors:
V. Costanzo, G. Belfiore, G. Granata, L. salvatorelli, P. Milone, G. magro, M. Ruggieri, A. Basile, S. Palmucci; Catania/IT
DOI:
10.1594/ecr2018/C-2697
Background
Tumors of peripheral nerve sheaths are divided into benign and malignant forms; the first group includes schwannomas and neurofibromas,
the second one includes their malignant counterpart: malignant schwannoma,
neurogenic sarcoma,
neurofibrosarcoma; these terms are not now currently used and are replaced by the term MPNSTs (Table 1) [1].
Table 1: Background of BPNSTs and MPNSTs.
References: Department of Medical-Surgical Sciences and Advanced Technologies - Radiology I Unit, University Hospital "Policlinico-Vittorio Emanuele" - Catania Italy
MPNSTs represent about 3-10% of all sarcomas,
in detail they include any sarcoma with at least one of the following features:
-arising from a peripheral nerve
-arising from a pre-existing benign nerve sheath tumor
-demonstrating Schwann cell differentiation on histologic examination [2].
These tumors may arise de novo (about 40% of cases),
after a previous radiation therapy (10% of cases) or in association with NF1 (up to 50% of cases).
Patients affected by NF1 may develop various types of neurofibromas such as localized,
diffuse and plexiform,
the latter shows malignant degeneration in about 5% of cases and is considered the real risk factor for the onset of MPNSTs [3,4].
MPNSTs have an incidence of 0.001% in the general population and occur mostly between 20 and 50 years of age with no gender predilection,
in patients with NF1 malignant tumors may occur earlier,
also in pediatric population [5].
BPNSTs are usually slow-growing painless masses instead MPNSTs cause rest pain and motor weakness due to nerve compression and infiltration.
When the tumor reaches large dimensions it can compress or infiltrate adjacent structures.
The first line of therapy- when possible- is a wide surgical excision; complications include local recurrences and metastasis,
especially in lung [6,7].