RESEARCH t u

lau Malignant peripheral nerve sheath tumors (MPNSTs) comprise a rare group of tumors that arise from differ-Predominant sites of presentation are the proximal ex-tremities and the pelvis [4]. They usually present as en-Jensen et al. Radiation Oncology (2015) 10:109 DOI 10.1186/s13014-015-0414-8scopic complete resection, local recurrence rates still ap-proach 20-38 % [3,4,8], which is even increasing in the Heidelberg, Germany Full list of author information is available at the end of the articleent cells found in the sheath of peripheral nerves includ-ing Schwann cells, perineural fibroblasts or fibroblasts, formerly known as malignant schwannoma, neurofibro-sarcoma, neurogenic sarcoma or malignant neurilemoma [1]. The reported incidence is 1:1000000 per year [2], representing 5-10 % of all malignant soft tissue tumors [3]. The most important risk factor is neurofibromatosis type I (NF I), which accounts for about half of the cases [1]. The incidence seems equal in males and females and larging mass, which may be associated with pain or neurological symptoms [2]. However, MPNSTs are highly aggressive tumors characterized by rapid, infiltrat-ing growth and hematogenous dissemination [1]. The preferred modality for imaging of MPNSTs is MRI [5] for the primary lesion and CT chest to exclude pulmon-ary metastases [6]. Complete resection with negative margins remains the mainstay of treatment but frequently results in func-tional deficits due to the inherent necessity to sacrifice the involved peripheral nerves [7]. Even after micro- * Correspondence