Review Question - QID 217430

The Figures show a very large anteromedial thigh soft tissue mass deep to the fascia, and the biopsy shows a high-grade undifferentiated pleomorphic sarcoma. High-grade sarcomas are routinely treated with a combination of radiation and wide surgical excision, followed by close postoperative surveillance monitoring for 5-10 years.

Soft tissue sarcomas (STS) of the extremities are a heterogeneous group of malignant tumors with individual inherent biological differences. Despite these differences, many are treated with a combination of wide surgical resection with neoadjuvant, intraoperative, or adjuvant radiation. Neoadjuvant radiation allows for lower overall radiation dose (50 gray) but has increased rates of postoperative wound complications. Adjuvant radiation is usually a higher overall dose (66 gray) and poses problems with late radiation toxicity, like development of secondary radiation associated sarcomas.

Endo and Lin review the role of surgical resection margins in extremity STS. They conclude that curative surgery should aim for at least microscopically negative margins and careful surgical planning should help determine intraoperative resection planes and resectable vs non-resectable anatomic structures. In certain highly invasive STS, such as myxofibrosarcoma the surgeon should prepare to achieve a margin of 3cm or more and consider the use of an intraoperative frozen section to determine a negative margin.

Shah et al review the role of radiation therapy in the management of extremity STS. They note that neoadjuvant radiation allows for a lower overall dose and improved long-term outcomes at the expense of increased wound complications. As radiation oncology continues to evolve, more localized treatment modalities such as brachytherapy and image-guided localized radiation can provide a smaller field of radiation with better local control and decreased complications. Also, tumor genetics will allow for the identification of which tumor subtypes are more responsive to radiation versus others and allow for better patient selection.

Figure A-C are the axial and coronal MRI images of a large, heterogeneous soft tissue mass in the anteromedial thigh, most consistent with a soft tissue sarcoma. The histology slide shows a high-grade lesion with cellular atypia in a chaotic arrangement, most consistent with undifferentiated pleomorphic sarcoma.

Incorrect Answers:
Answer 1: While hip disarticulation may provide adequate surgical margins, a purely soft tissue tumor in a location where soft tissue reconstruction and maintenance of limb function is possible, every effort should be made to preserve the limb.
Answer 2: Intralesional excision (tumor debulking) is not appropriate for this patient.
Answer 3: Radiation alone will not adequately treat this patient. Radiation is designed to help kill tumor cells in the periphery so that reliable surgical margins can be attained. Radiation is not designed to cause tumor atrophy and shrinkage.
Answer 5: Radiation and hip disarticulation would be a useful technique if preservation of limb function is not possible with wide resection. A purely soft tissue sarcoma that does not involve the important neurovascular bundles can be resected with local tissue reconstruction or free flap reconstruction and preserve limb function.