Enrico Martin

15 Introduction and thesis outline Table 2 Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) gradng system. Scoring system Definition Tumor differentiation 1 point Tumor closely resembling adult mesenchymal tissue 2 points Tumor for which histological typing is certain 3 points Embryonal and undifferentiated sarcomas Mitotic count 1 point 0-9 mitoses per 10 HPF 2 points 10-19 mitoses per 10 HPF 3 points ≥20 mitoses per 10 HPF Tumor necrosis 0 points No tumor necrosis 1 point ≤50% necrosis 2 points >50% necrosis Histological grade Grade 1 Total score of 2-3 Grade 2 Total score of 4-5 Grade 3 Total score of 6-8 HPF: high-power field their population size as few have been able to report on more than 100 patients. Then again, most were single center and single surgical subspecialty cohorts of patients. Functional status In STS literature, focus has remained on improving oncological outcome and diminishing postoperative complications. However, as STS are usually large tumors requiring major resections of soft tissues, postoperative morbidity can be significant, yet these outcomes have had little attention in literature. Although nowadays a limb-sparing approach is standard-of-care for extremity STS, amputations are still performed. Indications for amputations differ, but major neurovascular involvement is still often a reason for amputation, because of anticipated functional deficit. 33–35 It has additionally been shown in several studies that the resection of any nerve in extremity STS results in diminished function. 35–40 MPNSTs arise from nervous tissue and occur most commonly in the extremities, brachial plexus, or lumbosacral plexus. 11 Nevertheless, postoperative morbidity has rarely been studied in MPNST specifically even though they are at high risk of function loss by definition. In extremity STS generally, the resection of nerves may be prevented by epineural dissection whenever the tumor encases the nerve by less than 50-75%. 41,42 It is a technique in which the surgeon performs a planned positive margin thus requiring the administration of radiotherapy. This combination does not 1