Primary Tumor Resection in Leiomyosarcoma Patients With Synchronous Isolated Lung Metastases: A National Cancer Database Study.

INTRODUCTION: Up to half of patients with leiomyosarcoma (LMS) present with distant metastases, most commonly in the lungs. Despite guidelines around managing metachronous oligometastatic disease, limited evidence exists for synchronous isolated lung metastases (SILMs). Our histology-specific study describes management patterns and outcomes for patients with LMS and SILM across disease sites. METHODS: We used the National Cancer Database to analyze patients with LMS of the retroperitoneum, extremity, trunk/chest/abdominal wall, and pelvis with SILM. Patients with extra-pulmonary metastases were excluded. We identified factors associated with primary tumor resection and receipt of metastasectomy. Outcomes included median, 1-year, and 5-year overall survival (OS) across treatment approaches using log-rank tests, Kaplan-Meier curves, and Cox proportional hazard models. RESULTS: We identified 629 LMS patients with SILM from 2004 to 2017. Patients were more likely to have resection of their primary tumor or lung metastases if treated at an academic center compared to a community cancer center. Five year OS for patients undergoing both primary tumor resection and metastasectomy was 20.9% versus 9.2% for primary tumor resection alone, and 2.6% for nonsurgical patients. Median OS for all-comers was 15.5 mo. Community treatment site, comorbidity score, and larger primary tumors were associated with worse survival. Chemotherapy, primary resection, and curative intent surgery predicted improved survival on multivariate Cox regression. CONCLUSIONS: An aggressive surgical approach to primary LMS with SILM was undertaken for select patients in our population and found to be associated with improved OS. This approach should be considered for suitable patients at high-volume centers.

Safety and efficacy of percutaneous image-guided ablation for soft tissue sarcoma metastases to the liver.

PURPOSE: To evaluate outcomes following percutaneous image-guided ablation of soft tissue sarcoma metastases to the liver. MATERIALS AND METHODS: A single-institution retrospective analysis of patients with a diagnosis of metastatic soft tissue sarcoma who underwent percutaneous image-guided ablation of hepatic metastases between January 2011 and December 2021 was performed. Patients with less than 60 days of follow-up after ablation were excluded. The primary outcome was local tumor progression-free survival (LPFS). Secondary outcomes included overall survival, liver-specific progression-free survival. and chemotherapy-free survival. RESULTS: Fifty-five patients who underwent percutaneous ablation for 84 metastatic liver lesions were included. The most common histopathological subtypes were leiomyosarcoma (23/55), followed by gastrointestinal stromal tumor (22/55). The median treated liver lesions was 2 (range, 1-8), whereas the median size of metastases were 1.8 cm (0.3-8.7 cm). Complete response at 2 months was achieved in 90.5% of the treated lesions. LPFS was 83% at 1 year and 80% at 2 years. Liver-specific progression-free survival was 66% at 1 year and 40% at 2 years. The overall survival at 1 and 2 years was 98% and 94%. The chemotherapy-free holiday from the start of ablation was 71.2% at 12 months. The complication rate was 3.6% (2/55); one of the complications was Common Terminology Criteria for Adverse Events grade 3 or higher. LPFS subgroup analysis for leiomyosarcoma versus gastrointestinal stromal tumor suggests histology-agnostic outcomes (2 years, 89% vs 82%, p = .35). CONCLUSION: Percutaneous image-guided liver ablation of soft tissue sarcoma metastases is safe and efficacious.

[Radiation-induced parotid leiomyosarcoma]. / Léiomyosarcome parotidien en territoire irradié.

INTRODUCTION: First case of radiation-induced parotid leiomyosarcoma. ANATOMO-CLINICAL OBSERVATION: A 50-year-old woman with a history of cervical irradiation for Hodgkin's lymphoma presented with a right parotid tumefaction. Examination noted a deep adherent pretragal mass with peripheral facial palsy. A total parotidectomy with intra-operative examination and cervical curage was performed. Histopathological analysis concluded to a grade 3 parotid leiomyosarcoma according to the National Federation of Cancer Centers. Adjuvant radiotherapy was performed. After 24 months of follow-up, the patient presented bone and liver metastases without local recurrence. DISCUSSION: This is the first case of radiation-induced leiomyosarcoma and the 12th case of parotid leiomyosarcoma described in the literature. The management associates surgery with adjuvant radiotherapy. Follow-up is by clinical examination, parotid MRI, and annual thoracoabdominal CT scan to search for metastases. Recurrences occur during the first year in 40 to 64% of cases, and distant metastases in 40 to 60% of cases. The 5-year survival rate is between 10 and 30%.

Robot-assisted laparoscopic enucleation in the treatment of leiomyosarcoma of urinary bladder: A case report. / æœºå™¨äººè¾ åŠ©è ¹è ”é•œä¸‹å‰œé™¤æœ¯æ²»ç–—è†€èƒ±å¹³æ»‘è‚Œè‚‰ç˜¤1例.

Leiomyosarcoma of urinary bladder (LMS-UB) is a highly malignant mesenchymal tumor, accounting for less than 0.5% of all bladder malignancies, with a predominant clinical presentation of hematuria. Here we report a case of low-grade LMS-UB. A 44-year-old male patient was admitted to the hospital with urodynia for 2 weeks. The patient's pelvis CT showed a mass on the right part of the bladder. For this reason, he was initially diagnosed with bladder cancer. We performed a robot-assisted laparoscopic enucleation of the bladder tumor and low-grade LMS-UB was diagnosed with the histopathological examination. He underwent 5 cycles of adjuvant chemotherapy after surgery. At 19months postoperative follow-up, the patient had no symptoms, recurrence, or distant metastasis. There is no report on the treatment of LMS-UB with minimally invasive enucleation worldwide. This case provides a new comprehensive treatment method of enucleation combined with adjuvant chemotherapy for early low-grade LMS-UB to reduce complications and improve patients' quality of life after surgery.

Efficacy thresholds for clinical trials with advanced or metastatic leiomyosarcoma patients: A European Organisation for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group meta-analysis based on a literature review for soft-tissue sarcomas.

BACKGROUND: In 2002, the European Organisation for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group reported well-established values for conducting phase II trials for soft-tissue sarcomas. An update is provided for leiomyosarcoma (LMS). MATERIALS AND METHODS: Clinical trials with advanced or metastatic LMS were identified via literature review in PubMed (published 2003-2018, ≥10 adult LMS patients). End-points were 3- and 6-month progression-free survival rates (PFSR-3m and PFSR-6m). When estimates could not be derived from publications, data requests were sent out. Treatments were classified as recommended (R-T) or non-recommended (NR-T) according to the ESMO 2018 guidelines. A random effects meta-analysis was used to pool trial-specific estimates for first-line (1L) or pre-treated (2L+) patients separately. The ESMO Magnitude of Clinical Benefit Scale was used to guide the treatment effect to target in future trials. RESULTS: From 47 studies identified, we obtained information on 7 1L and 16 2L+ trials for 1500 LMS patients. Overall, in 1L, PFSR-3m and PFSR-6m were 74% (95% confidence interval [CI] 64-82%) and 58% (95% CI 50-66%), respectively. For 2L+, PFSR-3m was 48% (95% CI 41-54%), and PFSR-6m was 28% (95% CI 22-34%). No difference was observed between R-T and NR-T for first or later lines. Under the alternative that the true benefit amounts to a hazard ratio of 0.65, a PFSR-6m ≥70% can be considered to suggest drug activity in 1L. For 2L+, a PFSR-3m ≥62% or PFSR-6m ≥44% would suggest drug activity. Specific results are also provided for uterine LMS. CONCLUSIONS: This work provides a new benchmark for designing phase II studies for advanced or metastatic LMS.

Uncertainties that threaten the benefit/risk balance in early treatment lines for advanced or metastatic soft tissue sarcoma.

Sarcoma oncologists face many uncertainties which can threaten the benefit/risk balance during early management of patients with advanced or metastatic soft tissue sarcoma. This point is illustrated by a clinical case involving an elderly patient with comorbidities and a diagnosis of metastatic leiomyosarcoma. The patient was not a candidate for doxorubicin-based chemotherapy because of his cardiac history and was hesitant about systemic chemotherapy, ultimately expressing a preference for a well-tolerated regimen. After evaluating the treatment alternatives, trabectedin was chosen based on its indication for use in persons unsuited to receive anthracyclines and evidence supporting its efficacy and safety in elderly patients. The patient received 17 cycles of trabectedin for a best response of stable disease with good quality of life.

Proton radiotherapy for recurrent or metastatic sarcoma with palliative quad shot.

Patients with previously treated, recurrent or metastatic sarcomas who have progressed on multiples lines of systemic therapy may have limited options for local control. We evaluated outcomes of palliative proton therapy with the quad shot regimen to unresectable disease for patients with recurrent and/or metastatic sarcoma. From 2014 to 2018, 28 patients with recurrent or metastatic sarcomas were treated to 40 total sites with palliative proton RT with quad shot (14.8 Gy/4 twice daily). Outcomes included toxicity, ability to receive further systemic therapy, and subjective palliative response. Univariate analysis was performed for local progression-free survival (LPFS) and overall survival (OS). Of the 40 total sites, 25 (62.5%) received ≥3 cycles with median follow up of 12 months (IQR 4-19). The most common histologies were GIST (9; 22.5%) and leiomyosarcoma (7; 17.5%). A total of 27 (67.5%) sites were located in the abdomen or pelvis. Seventeen (42.5%) treatments involved concurrent systemic therapy and 13 (32.5%) patients received further systemic therapy following proton therapy. Overall subjective palliative response was 70%. Median LPFS was 11 months and 6-month LPFS was 66.1%. On univariate analysis, receipt of four cycles of quad shot (HR 0.06, p = 0.02) and receipt of systemic therapy after completion of radiation therapy (HR 0.17, p = 0.02) were associated with improved LPFS. Three grade 3 acute toxicities were observed. The proton quad shot regimen serves as a feasible alternative for patients with previously treated, recurrent or metastatic sarcomas where overall treatment options may be limited.

Recurrent vaginal epithelioid leiomyosarcoma; a case report from Botswana and review of the literature.

Primary vaginal leiomyosarcoma is a rare gynecological malignancy. The clinical presentation is a benign looking well circumscribed mobile mass which might however occasionally present with distant metastases. Post treatment recurrence is common, and the clinical course is often unpredictable. Primary surgical management plus radiotherapy is the commonly practiced treatment of choice. We report a case of primary vaginal epithelioid leiomyosarcoma that recurred twice after local surgical resection. The patient subsequently underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy for a recurrent vaginal leiomyosarcoma. Histopathology of the vaginal mass revealed an epithelioid leiomyosarcoma of the vagina. She also received a course of adjuvant radiotherapy. The patient was free of recurrence at 3 year follow up. Vaginal mass must be evaluated with a high index of suspicion for malignancy. Local surgical resection alone is insufficient for primary vaginal leiomyosarcoma. Surgical resection with adjuvant radiotherapy offers better treatment outcomes with decreased risk of recurrence. Empirical oophorectomy in patients with completed family size might confer additional benefit in preventing disease recurrence in resource limited settings where testing for estrogen and progesterone receptor status of the tumour is unavailable. Due to the unpredictable course of the disease, lifelong patient follow-up is critical for better outcomes.

Gastrointestinal leiomyosarcoma demonstrate a predilection for distant recurrence and poor response to systemic treatments.

BACKGROUND: Primary leiomyosarcoma (LMS) of the gastrointestinal (GI) tract is rare. Limited literature exists regarding the clinical characteristics and outcome for patients with localised and metastatic disease. METHODS: A retrospective chart review was performed for patients greater than 18 years of age diagnosed with GI LMS at The Royal Marsden Hospital between 1 January 2000-1 May 2020. Descriptive statistics were performed. Patients were censored at data cut-off date of 27 June 2020. RESULTS: Forty-six patients with a median age at diagnosis of 54 years (range 25-85) were identified. Fifteen percent (n = 7) of patients previously received abdominal radiation for an unrelated cancer. All patients with localised disease (n = 36) had resection with oncological margins. For patients who underwent potentially curative surgery, median recurrence-free survival (mRFS) was 13 months (0.4-183 months), and half of these patients (n = 18) developed recurrent disease post resection (distant n = 16, local n = 2). Median overall survival (mOS) was 27 months for patients with distant recurrence. Twenty-one percent (n = 10) of patients presented with synchronous metastatic disease and their mOS was 19 months. Median progression-free survival (mPFS) for patients treated with conventional chemotherapy ranged from 2.0 to 8.0 months. CONCLUSION: The risk of recurrence is significant, and recurrence-free survival was short even with complete oncologic resection. The relationship of prior abdominal radiotherapy to the development of GI LMS warrants further investigation. Outcomes with systemic therapy for metastatic disease were poor and there is a need for the development of more effective systemic therapies.

Uterine leiomyosarcomas with osteoclast-like giant cells associated with high expression of RUNX2 and RANKL.

Uterine leiomyosarcoma (ULMS) with osteoclast-like giant cells (OLGCs) has been reported as a rare phenomenon in ULMS, and its clinico-pathological features and tumorigenesis remain unclear. We recently reported high expression of receptor activator of nuclear factor κB ligand (RANKL) in ULMS with OLGCs. As osteoblasts produce RANKL, in this study, we analyzed the expression of Runt-related transcription factor 2 (RUNX2), a critical transcription factor for osteoblasts, and osteoclast-related proteins in three cases of ULMS with OLGCs as well as five conventional ULMSs and nine leiomyomas. Immunohistochemistry and real-time reverse transcription quantitative polymerase chain reaction analyses showed high expression of RUNX2 and RANKL in ULMS with OLGCs. In these cases, macrophages expressed receptor activator of nuclear factor κB (RANK), and OLGCs expressed osteoclast-related proteins (nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), and cathepsin K). Accumulation sites of cathepsin K-positive OLGCs showed hemorrhagic appearance and degraded type IV collagen. We reviewed reported cases of ULMS with OLGCs, including ours, and found that they presented an aggressive course even at stage I. Furthermore, metastatic lesions showed similar histological features to those of OLGC association in ULMS. Here, we show that tumor cells in ULMS with OLGCs highly express RUNX2 and RANKL and that osteoclastic differentiation of macrophages occurs in the tumor tissue.

A late systemic and brain metastasis from subcutaneous leiomyosarcoma of the right forearm: a case report and review of the literature.

BACKGROUND: Leiomyosarcomas are rare malignant tumors which originate from smooth muscle cells and very seldom give rise to intracerebral metastases. Nearly all cases of intracranial metastases stem from leiomyosarcomas of the uterus. We present a 61-year-old Caucasian man who developed multiple intracranial and extracranial metastases from leiomyosarcoma of the right forearm, diagnosed and treated 9 years before the current presentation. CASE PRESENTATION: The Caucasian patient presented to the emergency department due to a progressive hemiparesis on the left side. Magnetic resonance imaging scans of the neurocranium showed multiple intracerebral masses with perifocal edema. One of these was located in the right parietal lobe, corresponding to the hemiparesis. The patient underwent microsurgical complete resection of the parietal mass and was subsequently subjected to further radiotherapy. Histopathological studies revealed metastasis of the former leiomyosarcoma. CONCLUSIONS: Leiomyosarcomas represent a rare entity of mesenchymal tumors. Intracerebral metastasis of these tumors is even less frequent. This case shows the importance of long-term follow-up in patients with leiomyosarcoma.

Neck subcutaneous nodule as first metastasis from broad ligament leiomyosarcoma: a case report and review of literature.

BACKGROUND: Leiomyosarcoma usually develops in the myometrium and is characterized by a high recurrence rate, frequent hematogenous dissemination, and poor prognosis. Metastasis is usually to lungs, liver, and bone, and occasionally to the brain, but seldom to the head and neck region. Primary leiomyosarcoma very rarely arises in the broad ligament. CASE PRESENTATION: A 54-year old woman presented to the otolaryngology department with a mass in the right posterior region of the neck 4 years after surgery for a primary leiomyosarcoma of the right broad ligament. The neck mass was removed and found to be a metastatic leiomyosarcoma. Leiomyosarcoma localizations in lungs and liver were absent. Morphological examination showed both the primary and the secondary leiomyosarcomas to have features of low-grade tumors. One year after excision of the neck mass, the patient presented with tachycardia. Echocardiography detected two intracardiac nodules suggestive of metastatic tumors. Chemotherapy was administered; the disease has been stable since then. CONCLUSIONS: We report the first case of broad ligament leiomyosarcoma with the neck subcutaneous region being the first site of secondary involvement. We speculate that the Batson venous plexus might have been the pathway of dissemination.

[Resection of retroperitoneal leiomyosarcoma followed by replacement of cavarenal segment of inferior vena cava]. / Udalenie zabryushinnoi leiomiosarkomy s rezektsiei i protezirovaniem kavarenal'nogo segmenta nizhnei poloi veny Klinicheskoe nablyudenie.

The authors reported a rare clinical case of successful surgical treatment of young female with retroperitoneal leiomyosarcoma followed by lesion of the cavarenal segment of inferior vena cava, left renal vein. Clinical and morphological features of disease, postoperative outcomes and prognostic factors in patients with retroperitoneal leiomyosarcoma are discussed.

Liver resection for sarcoma metastases: A systematic review and experience from two European centres.

INTRODUCTION: Studies reporting outcomes of liver resection for sarcoma metastases (LRSM) typically include gastrointestinal stromal tumours (GIST), or pooled analyses of "non-colorectal liver metastases", which do not reflect the subgroup of patients with sarcomatous liver metastases. This study aimed to perform a systematic review to evaluate oncological and surgical outcomes in patients undergoing LRSM, and to report new data from two tertiary institutions. METHODS: MEDLINE and the Cochrane Library were searched for studies reporting oncological and surgical outcomes after LRSM, following PRISMA guidelines. Studies reporting liver resection for GIST were excluded. The resulting studies were pooled, with data from two European centres. RESULTS: Six studies of LSRM were included, comprising 212 patients from previously reported series and 24 patients from ours, with median follow-up times of 18-53 months. Postoperative mortality rates ranged from 0 to 9%, and the pooled overall survival (OS) was 89% (95% CI: 83-96%), and 31% (95% CI: 14-47%) at one and five years, respectively (median: 36 months). The presence of synchronous extra-hepatic metastases was found to be a significant risk factor for shorter OS in two cohorts, with hazard ratios of 3.7 (p < 0.001) and 9.1 (p = 0.016), respectively. The largest reported series also found larger metastases (≥100 mm), lack of response to chemotherapy and a shorter disease-free interval to be associated with significantly shorter OS after LSRM. CONCLUSIONS: Patients undergoing LRSM with negative prognostic factors such as the presence of extra-hepatic metastases are unlikely to benefit from surgery. Acceptable medium- and long-term survival may be achievable in highly selected patients.

Vulvar sarcoma outcomes by histologic subtype: a Surveillance, Epidemiology, and End Results (SEER) database review.

OBJECTIVE: Vulvar cancers account for 5% of all gynecologic malignancies; only 1%-3% of those vulvar cancers are primary vulvar sarcomas. Given the rarity of vulvar sarcomas, outcome data specific to histopathologic subtypes are sparse. The aim of this study was to identify clinical and pathologic factors of primary vulvar sarcomas that are associated with survival and may inform treatment decisions. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was searched for women diagnosed with vulvar sarcoma between 1973 and 2018. We identified 315 patients and reviewed their demographic, clinicopathologic, surgical, and survival information. Statistical analyses included χ2 and t-tests, Kaplan-Meier survival, and Cox regression analyses. RESULTS: The most common histopathologies of vulvar sarcomas were dermatofibrosarcomas (85/315, 27%) and leiomyosarcomas (72/315, 22.9%). Rhabdomyosarcomas (18/315, 5.7%), liposarcomas (16/315, 5.1%), and malignant fibrous histiocytomas (16/315, 5.1%) were less frequent. The majority of patients underwent surgery (292/315, 92.7%), which included lymph node dissections in 21.6% (63/292). Survival and lymph node involvement varied significantly with histologic subtype. The 5-year disease-specific survival for dermatofibrosarcomas, liposarcomas, and fibrosarcomas was 100% and only 60.3% and 62.5% for malignant fibrous histiocytomas and rhabdomyosarcomas, respectively. None of the patients with (dermato)fibrosarcomas, liposarcomas, or leiomyosarcomas had positive lymph nodes, in contrast to rhabdomyosarcomas and malignant fibrous histiocytomas with 77.8% and 40% positive lymph nodes, respectively. The 5-year disease-specific survival for women with positive lymph nodes was 0%. CONCLUSIONS: Vulvar sarcomas are heterogeneous with survival highly dependent on the histopathologic subtype. While surgical excision is the mainstay of treatment for all vulvar sarcomas, staging lymphadenectomy should be deferred for (dermato)fibrosarcomas, liposarcomas, and leiomyosarcomas as there were no cases of lymph nodes metastases.

Recurrent broad ligament leiomyosarcoma with pancreatic and thigh metastasis: a case report.

BACKGROUND: Leiomyosarcoma (LMS) is an uncommon mesenchymal neoplasm, which infrequently metastasizes to pancreas and thigh. Clinical presentation and imaging findings of metastatic broad ligament LMS are often nonspecific. Complete excision plays an important role in treatment of patients with localized LMS. CASE PRESENTATION: Here, we report a case of a 33-year-old woman with recurrent broad ligament LMS metastasizing to pancreas and thigh. Previously, she was diagnosed with broad ligament LMS and underwent hysterectomy, bilateral salpingo-oophorectomy. The disease-free interval was 2.5 years until metastases were found. Computerized tomography (CT) of abdomen and thighs, magnetic resonance imaging (MRI) of thighs and whole-body 18-fluorodeoxyglucose positron emission tomography - computed tomography (PET-CT) performed, revealed pancreatic and thigh metastasis. Ultrasonography-guided biopsy and histological examinations confirmed LMS at both the sites. Pancreatic metastasis was completely resected first. Then the patient underwent surgical resection of thigh metastasis when both chemotherapy and radiotherapy failed. She recovered well and remained free of disease recurrence in the 2 years follow-up. CONCLUSIONS: Though imaging lacks specificity, it is a valuable asset in assessing the burden of disease and characterizing lesions while histological examination with immunohistochemistry is helpful for the diagnosis of LMS. Complete surgical resection of all metastatic sites where-ever feasible should be strongly considered in a treated case of broad ligament LMS with a durable disease-free interval.

Metastases of soft tissue sarcoma to the liver: A Historical Cohort Study from a Hospital-based Cancer Registry.

BACKGROUND: Hepatic metastasis of soft tissue sarcoma is rare compared to lung metastasis, and the literature is scarce. We examined the risk of hepatic metastasis according to the site of occurrence and histological type. METHODS: From a Hospital-based Cancer Registry, 658 patients registered between 2007 and 2017 with soft tissue sarcomas were evaluated. The exclusion criteria were gastrointestinal stromal tumors, tumors of unknown origin, and follow-up periods of less than 1 month. SPSS 25 was used for statistical analysis. RESULTS: The risk of hepatic metastasis was significantly higher in the retroperitoneum (HR, 5.981; 95% CI, 2.793-12.808) and leiomyosarcoma (HR, 4.303; 95% CI, 1.782-10.390). Multivariate analysis showed that the risk of hepatic metastasis as first distant metastasis was high in leiomyosarcoma (HR, 4.546; 95% CI, 2.275-9.086) and retroperitoneal onset (HR, 4.588; 95% CI, 2.280-9.231). The 2-year survival rate after hepatic metastasis was 21.7%. CONCLUSIONS: The onset of hepatic metastasis indicates a poor prognosis. However, hepatic metastasis from retroperitoneal sarcoma and leiomyosarcoma may be the first distant metastasis in some cases. For retroperitoneal sarcoma and leiomyosarcoma, additional screening for hepatic metastasis such as contrast CT should be considered during staging and follow-up after treatment.

Cardiac metastasis of great saphenous vein leiomyosarcoma.

We present a case with cardiac metastasis of the great saphenous vein leiomyosarcoma (LMS) that presented to the emergency department with dyspnea and palpitations 2 months ago. In this patient, hemodynamic instability was caused by an extensive right ventricular cavity and outflow tract invasion of the LMS. Treatment of the patient included incomplete mass resection, adjuvant chemotherapy, and permanent pacemaker implantation (due to postoperative complete atrio-ventricular block).

Cutaneous leiomyosarcoma: dermal and subcutaneous.

BACKGROUND AND OBJECTIVES: Leiomyosarcoma of skin (LMS) can be sub-classified on pathology appearances as Dermal or Subcutaneous. The aim of this study was to provide treatment recommendations for these uncommon tumours. METHODS: A retrospective review of all patients with dermal and subcutaneous leiomyosarcoma managed at the Peter MacCallum Cancer Centre, Australia from January 2003 to December 2018 was performed. Eighty-three patients were identified (64 dermal leiomyosarcoma, 19 subcutaneous leiomyosarcoma). RESULTS: Subcutaneous leiomyosarcoma were larger (median size 14 mm dermal, 49 mm subcutaneous, P = 0.01). No patient with a dermal leiomyosarcoma developed metastatic disease compared to 4 of the 19 subcutaneous leiomyosarcoma (5-year overall survivals, 98% and 88%, respectively, P = 0.03). The most common site of metastasis was to the lung. No difference in risk of local recurrence was apparent (5-year recurrence-free survivals were 85% and 78%, respectively, P = 0.17). Adjuvant radiotherapy was used in 16 (25%) dermal leiomyosarcoma patients and 13 (68%) subcutaneous leiomyosarcoma patients (P < 0.001). Local recurrence was uncommon in both tumour subtypes when patients received definitive surgical excision (minimum histological margins of 10 mm as per institutional protocol) regardless of whether radiotherapy was used. The 5-year local recurrence-free survival for dermal leiomyosarcoma treated with radiotherapy was 93% versus 83% without radiotherapy (P = 0.7) and for subcutaneous leiomyosarcoma was 69% and 100%, respectively (P = 0.9). CONCLUSIONS: Dermal leiomyosarcoma have an excellent prognosis, particularly after definitive surgical excision with margins of at least 10 mm. Subcutaneous leiomyosarcoma has poorer outcomes and should be managed by wider excision and considered for adjuvant radiotherapy.