Buttock Soft Tissue Sarcoma: Clinical Features, Treatment, and Prognosis

Outcome with Surgical Treatment of Canine Soft Tissue Sarcoma in the Region of the Ischiatic Tuberosity: A Veterinary Society of Surgical Oncology Retrospective Study

OBJECTIVE

To determine the outcome of dogs with soft tissue sarcoma (STS) within the region of the ischiatic tuberosity (ITSTS) treated surgically.

STUDY DESIGN

Multi-institutional retrospective study ANIMALS: Fifty-two client-owned dogs with histologically confirmed STS in the region of the IT treated with surgical resection between March 1st, 2009, and March 1st, 2021, and a minimum follow-up time of six months.

METHODS

Data collected included signalment, preoperative diagnostics, surgical intent/method, complications, histopathology, margins, outcome, and cause of death. Statistical analyses were performed to determine significant factors in treatment and prognosis of ITSTS.

RESULTS

Fifty-two dogs with histopathologically-confirmed ITSTS included resulting in 24 grade I, 20 grade II, and seven grade III tumors. Overall survival time and disease progression were negatively associated with tumor grade while recurrence was positively associated with grade and incomplete margins. Overall survival time and progression-free survival time was not reached for tumors graded as I or II and was 255 and 268 days respectively for grade III. Median time to recurrence was not reached for tumors excised with complete margins and 398 days for incomplete margins. There was a 25% reported surgical complication rate.

CONCLUSION

Ischiatic tuberosity soft tissue sarcoma was not found to be a unique clinical entity in dogs. Treatment recommendations and prognosis were similar to STS in other locations. The outcome was influenced by histologic grade and margins.

CLINICAL SIGNIFICANCE

Ischiatic tuberosity soft tissue sarcoma of dogs does not behave more aggressively than those in other locations. Surgical complications were common but not life-threatening. Overall prognosis, including survival and disease recurrence, appears to depend on histological grade and surgical margins. This article is protected by copyright. All rights reserved.

Free Neurovascular Latissimus Dorsi Muscle Transplantation for Reconstruction of Hip Abductors

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Resection of tumors affecting the hip abductors can cause significant decrease in muscle strength and may lead to abnormal gait and poor function. We present a case report showing full functional recovery after resection of a synovial sarcoma affecting the right gluteus medius and minimus muscles with reconstruction free neurovascular latissimus dorsi muscle transplantation. The latissimus dorsi muscle was harvested following standard technique and fixed to the ilium and the greater trochanter. Receptor vessels were end-to-end anastomosed to the subscapular vessels followed by an end-to-end epineural suture between the superior gluteal nerve and the thoracodorsal nerve. A year after surgery, there is no evidence of recurrent disease; electromyographic analysis shows complete reinnervation of the latissimus dorsi muscle flap, and the patient has achieved full functional recovery. Free functional latisimus dorsi transfer could be considered as a viable reconstruction technique after hip abductors resection in tumor surgery.

Primary high-grade soft-tissue sarcoma of the buttock: a rare but distinct clinical entity

OBJECTIVE

Sarcoma arising in the region of the buttocks is a rare entity and therefore no consensus regarding management exists in the literature.

METHODS

16 patients diagnosed with localized, non-metastatic primary soft-tissue sarcoma (STS) in the buttock area, who were consecutively treated between 2005 and 2013, were retrospectively evaluated for the rate of local control, distant metastases and overall survival.

RESULTS

Most tumours were classified as high grade (87.5%). The average time between the appearances of symptoms to diagnosis of sarcoma was 4.5 months. At the end of the observation period, 7 (44%) patients were alive without signs of progressive disease, 37.5% patients died as the disease progressed, 13 patients were free of disease and 3 (19%) patients were alive with signs of progressive disease. Seven (44%) patients developed local recurrence. Six (37.5%) patients developed distant metastases. The lung was the most common site of distant failure (four patients); other sites were the liver as well as the adrenal gland and kidney (one patient). Four patients had both distant and local progression, three patients experienced isolated local recurrence and two patients developed isolated distant metastases. 5-year local recurrence-free survival was 58% and 5-year distant metastases-free survival was 63%.

CONCLUSION

It is unclear whether to subsume STS of the buttock under the rubric of pelvic tumours or tumours of the lower extremity. Either way, STS of the buttock seems to be characterized by local control, freedom from distant relapse and survival, which is inferior to accepted standards for either pelvic or lower extremity sarcomas. To improve this poor outcome, oncologists are encouraged to regard sarcoma of the buttock as a distinct clinical entity and to devise innovative therapeutic strategies accordingly.

ADVANCES IN KNOWLEDGE

Sarcoma of the buttock area should possibly be regarded as a distinct entity.

Recurrence and survival analysis of resected soft tissue sarcomas of pelvic retroperitoneal structures

BACKGROUND

The purpose is to determine the clinicopathologic factors related to survival and recurrence of primary resected pelvic soft tissue sarcomas (STS).

METHODS

Demographic/clinical variables were recorded.

RESULTS

Thirty-five pts were identified. Median follow-up was 24.2 months. There were 23 (65.7%) high/intermediate-grade and 12 (34.3%) low-grade tumors included in the final analysis. Eight patients (22.9%) received neoadjuvant therapy. Margins were grossly negative in 27 (77.1%, 17-R0, 10-R1) and grossly positive (R2) in 8 (22.9%). Adjuvant therapy was used in 13 patients (37.1%). The 2- and 3-year RFS was 56.5% and 51.3%, with 14 patients recurring at a median time of 16 months (6-local, 8-distant). All distant recurrences were in high-grade tumors. There were no differences in RFS for margins (R0 vs. R1), neoadjuvant/adjuvant therapy, size (≥10 vs. <10 cm) or gender. High/intermediate-grade tumors had worse RFS (P < 0.008). The 2- and 3-year OS was 80.9%. OS was improved for R0/R1 resection (P < 0.001). Resection to R0/R1 margin was a significant predictor of improved OS (P = 0.001).

CONCLUSIONS

High/intermediate-grade lesions were associated with worse OS and RFS. Resection to gross negative margins was the only independent predictor of OS. Adjuvant therapy may be reserved for high-grade lesions due to increased metastatic potential. J

Tail-end troubles: imaging of soft-tissue buttock tumours

Primary soft-tissue buttock tumours are relatively common entities, although they are infrequently reported in the literature. The buttock can be a difficult anatomical site to treat soft-tissue tumours due to the proximity of the sciatic nerve and the propensity of tumours at this site to extend into the pelvis and perineum. Therefore, the radiologist plays an important role in the multidisciplinary assessment of these lesions. Cross-sectional imaging, principally magnetic resonance imaging, is used to determine the exact location and extension of the tumour. Furthermore, certain tumours have characteristic imaging appearances that can help to establish a suitably ordered differential diagnosis. From our prospectively maintained database at The Royal Marsden Hospital, including 225 cases that were treated at the Sarcoma Unit over a 30 year period, we present examples of benign and malignant primary soft-tissue buttock tumours and describe the pertinent imaging characteristics, with emphasis on computed tomography and magnetic resonance imaging findings.