ML accounts for one-third of liposarcomas and represents a morphologic continuum encompassing myxoid and myxoid/round cell variants, the latter characterized by an extent of round cell components greater than five percent [
6]. The molecular hallmark of ML is the presence of FUS-CHOP fusion proteins, with surgery and radiochemotherapy the standard therapy for localized ML. Surgery must include a wide excision with negative margins (R0). While 1cm has been selected as a cut-off point in some studies, it is important to realize that the margin can be minimal in the case of resistant anatomical barriers, such as muscular fasciae, periosteum and perineurium. Wide excision followed by radiation therapy is standard treatment in high-grade, deep lesions, >5cm. In the case of low-grade, deep, >5cm soft tissue sarcoma, radiation therapy should be discussed in a multidisciplinary fashion, taking into account the anatomical site and the related expected sequelae versus the histological aggressiveness. Overall, radiation therapy has been shown to improve local control, but not overall survival. Radiation therapy should be administered post-operatively, with the best technique available, at a dose of 50 to 60Gy, with fractions of 1.8 to 2Gy, possibly with boosts up to 66Gy depending on presentation and quality of surgery. Alternatively, radiotherapy may be carried out pre-operatively, normally using a dose of 50Gy. Intra-operative radiation therapy (IORT) and brachytherapy are also options for selected cases [
3]. In our patient’s case, adjuvant treatment with external radiotherapy was considered even though she had a low-grade LPS because of its size (10cm) and because adequate margins could not be achieved. Our patient did not receive adjuvant chemotherapy. The results of some studies have shown that adjuvant chemotherapy might improve, or at least delay, distant and local recurrence in high-risk patients. However, a final demonstration of efficacy is lacking. It is also unknown whether adjuvant chemotherapy may be especially beneficial in specific subgroups. Therefore, adjuvant chemotherapy is not a standard treatment in adult-type soft tissue sarcomas. Clinical practice guidelines propose adjuvant chemotherapy as an option for high-risk individual patients, which includes those having a >G1, deep, >5cm tumor [
6].
Our patient experienced three recurrences during a six-year period; two of them were managed with complete excision and the first was followed by adjuvant chemotherapy with ifosfamide and epirubicin for six months. Clinical guidelines recommend treating extrapulmonary disease recurrence with chemotherapy as standard. However, in selected cases, surgery of potentially resectable metastases may be offered as an option following a multidisciplinary evaluation, taking into consideration the site(s) and the natural history of the disease in the individual patient. Standard chemotherapy is based on anthracyclines as first-line treatment [
4,
6].
Only a few cases of recurrent LPS have been reported during pregnancy to date, and no solid evidence of an increased incidence or a worse outcome has been demonstrated. Trabectedin has shown activity in patients with STS with a response rate of eight percent and a 47 percent one-year survival. In a phase II study focused on patients with leiomyosarcomas and LPS, the agent demonstrated a 14-month median survival that is superior to the expected 12 months seen with historical controls [
7]. One issue in assessing the activity of new agents in STS is the criteria for response. Tumor size may increase or remain stable in responding patients because of necrosis, bleeding and myxoid degeneration. For this reason, new criteria integrating tumor size and tumor density have been proposed. Molecular analysis of this tumor showed a t(12,16) + translocation resulting in a FUS-DDIT3 or EWSR1-DDIT3 fusion that has been related in pre-clinical studies with the activity of trabectedin in myxoid LPS [
4].