Outcome of Soft Tissue Popliteal Sarcomas: 15 Years of Experience

Background: Soft-tissue sarcoma involving the popliteal fossa remains challenging because it is difficult to achieve wide margins with limb salvage in this location. Adjuvant therapy is frequently necessary, and limb function can be adversely affected. We reviewed our experience with these tumors. A variety of lesions can be identified within the posterior knee, ranging from simple Baker's cysts to malignant lesions. We present a review of frequently encountered and less common entities using an anatomic sieve, with the aim of providing a diagnostic approach to popliteal fossa masses Soft-tissue sarcomas (STSs) arising from the popliteal fossa present a challenge with regard to local control of primary tumors.

Method: In the study, patients who were operated for a mass in the popliteal region between 2007 and 2018 in our clinic were retrospectively analyzed. Patients were categorized by parameters such as age, gender, extremity direction, type of surgery, AJCC scores, surgical margin, tumor size, presence of distant metastases, mass pathology, follow-up time and MSTS score.

Results: Our study included 13 patients (eight women and five men). The mean age was 48 (range 12-84) years. The mass was located in the left knee in nine patients and the right knee in four patients. Frequent histologic diagnoses were for maliğn soft-tissue tumor liposarcoma (n= 5), synovial sarcoma (n= 3) and pleomorphic sarcoma (n= 2), rabdomyorsarcoma, clear cell sarcoma, peripheral nerve sheath tumor (n=1). Tumor size varied from 3 to 14 cm (median 7 cm). American Joint Committee on Cancer staging was as follows: three patients had stage IIA disease, five patients had stage IIB disease, two patients had stage III and stage IB and 1 patient had stage IV disease. The mean duration of follow-up was 39 (range 12-96) months. All patients underwent wide resection. Recurrence developed in four of these patients during the 5-year follow-up period. Recurrence resection was performed in three of the patients who developed recurrence, while recurrence resection + femur distal tumor resection arthroplasty was performed in one patient. In addition, 3 of these 13 patients received neoadjuvant chemotherapy, while 5 received adjuvant chemotherapy treatment. Neoadjuvant RT was applied to 4 patients with a mass greater than 9 cm. Margins were negative in seven of 13 patients and microscopically positive in five patients. Complications included wound infections in four patients and thrombophlebitis in two patients and one patients peroneal nerve nöropraxy. Of the patients undergoing limb-salvaging procedures, two experienced local recurrences after limb salvage and four experienced lung metastases. Local recurrence was always associated with positive margins. The mean MusculoskeletalTumor Society 1987 score was 50 ( range 35-68). At latest follow-up, six patients had died of disease, one was alive with disease, and five patients remained free of disease.

Conclusion: The popliteal region is a rare area in terms of mass localizations. Inpatients presenting with knee pain, regardless of external findings such as swelling ornot, tumors located in the popliteal region should be considered in patients withoutpathology on direct radiography.