Primary leiomyosarcoma of bone: analysis of prognosis

What Is the Impact of Multimodal Treatment in Patients with Leiomyosarcoma of Bone? A Multicenter Study of 35 Patients with an Ultra-Rare Tumor Entity

Primary leiomyosarcoma of bone (LMSoB) is extremely rare, comprising only <0.7% of primary malignant bone tumors, and is therefore considered an ultra-rare tumor entity. There is currently no consensus as to whether therapeutic strategies should be based on the biological characteristics of soft tissue leiomyosarcoma or on primary tumor localization in the bone. The use of perioperative chemotherapy and its effectiveness in this rare tumor entity remains unclear. We aimed to evaluate the impact of different treatment approaches in a multicenter setting with a total of 35 patients included. The 5-year overall survival (OS) was 74%. Patients with localized disease undergoing surgery had a significantly higher 5-year OS compared to patients who did not undergo surgical treatment (82% vs. 0%, p = 0.0015). Axial tumor localization was associated with worse event-free survival (EFS) probability (p < 0.001) and OS (p = 0.0082). A high proportion of our patients developed secondary metastases. Furthermore, the perioperative chemotherapy protocols applied to our patients were not associated with an improved EFS or OS. Therefore, the benefit of perioperative chemotherapy in LMSoB needs to be further investigated, and the choice of agents still needs to be clarified.

Leiomyosarcoma of the bone: Unveiling the mystery of a spindly ossein

ABSTRACT

Leiomyosarcoma (LMS) represents one of the most common soft tissue sarcomas, involving various anatomical sites like the retroperitoneum, genitourinary tract, and extremities. LMS of the bone is extremely rare, with a 0.7% incidence of all primary malignant bone tumors. They are histologically identical to the leiomyosarcomas of other sites but pose a diagnostic dilemma due to their rarity and varied presentation when it manifests as a bony lesion.

Primary leiomyosarcoma of the bone: a case report

Primary leiomyosarcoma of the bone is rare. Histologically, it resembles leiomyosarcoma of soft tissue. Given the rarity of this entity, its diagnosis should be made only after clinical studies and workup have excluded metastasis from other sites. Herein, we describe an additional case of primary bone leiomyosarcoma. We report a 32-year-old female patient, who presented with right knee pain and was found to have a right distal femur mass by imaging studies. Biopsy showed a neoplasm composed of fascicles of spindle cells, arranged in different patterns, with significant pleomorphism. The tumor cells were positive for smooth muscle actin, focally positive for desmin and H-caldesmon. No other masses in the body were detected by imaging studies. The diagnosis of leiomyosarcoma of the bone was rendered. Given the broad diagnostic differential of primary bone leiomyosarcoma, it is important to be aware of this rare bone tumor phenotype and of its histomorphologic and immunohistochemical features for an accurate diagnosis.

Case report and literature review: Primary leiomyosarcoma of the bone in the trochanteric region of the femur

Background

Primary leiomyosarcoma of the bone (LMSB) is an extremely rare, invasive, and highly destructive primary osteosarcoma with limited treatment options and poor prognosis. Only a few case reports of LMSB have been described because of its rarity. Therefore, clinicians have a limited understanding of its diagnosis, treatment, and prognosis, and the final diagnosis depends on histopathological findings. In this report, we describe a rare case of primary LMSB in the trochanteric region of the femur. Reporting this case may increase the dissemination and understanding of information regarding LMSB and provide a reference for the diagnosis and treatment of similar cases.

Case presentation

A 63-year-old woman presented with pain and limited movement of the left hip, which had lasted for 3 months, with no history of trauma or illness. Plain radiography and computed tomography revealed a solitary osteolytic lesion in the trochanteric area of the left femur with focal cortical destruction. Magnetic resonance imaging findings suggested invasion of the lesion into the bone cortex, forming a soft tissue mass, although no distant positive findings were observed on a whole-body bone scan. A bone tumor puncture biopsy was performed to obtain a final diagnosis, and histopathological evaluation revealed left femoral intertrochanteric leiomyosarcoma, classified as G1T2M0 and staged as IB (extracompartmental low-grade malignant) according to the Enneking staging system. Thus, we performed extensive debridement and left hip arthroplasty. Postoperative chemotherapy was administered, and the patient was followed up for 4 years. Four years later, the patient's left hip pain had resolved, joint activity was good, and no signs of recurrence or distant metastasis of the bone tumor were noted.

Conclusion

For proximal femoral Enneking stage IB LMSB, extensive tumor resection combined with tumor prosthesis replacement may be an effective treatment method to prolong the patient's lifespan and to restore joint function.

Primary Osseous Leiomyosarcoma with Vertebral and Nodal Metastasis in a Young Woman: A Rare Case Report

Introduction. Primary leiomyosarcoma of bone is rarely described in the literature. In young patients, the clinical and radiological features may mimic relatively common tumours like osteosarcoma. Vertebral and nodal metastasis from osseous leiomyosarcoma is extremely uncommon. Case presentation. A 25-year-old female presented with progressively increasing pain and swelling of the right knee. Clinical and radiological features were suggestive of osteosarcoma. Pre-operative biopsy showed a malignant spindle cell tumour. The surgical resection specimen showed features of leiomyosarcoma of the right proximal tibia. On further evaluation, the patient was found to have an L3-L4 vertebral lesion and histopathological evaluation showed a similar tumour. After 11 months of initial presentation, the patient had axillary lymph node metastasis. Conclusion. Primary osseous leiomyosarcoma should be considered as a differential diagnosis even in young patients presenting with meta-diaphyseal expansile malignant bony lesions. Histology and ancillary studies can confirm the diagnosis.

Primary bone leiomyosarcoma of distal femur: case report and literature review

We present the case of a 58-year-old patient presented with a spontaneous right supracondylar fracture. The initial bone biopsy, highlighted the defining histopathological (HP) elements for a leiomyosarcoma (LMS), initially considered a metastasis. The complex imaging examinations did not reveal another tumor, so the final diagnosis was primary bone LMS. Final treatment was a wide tumor resection and reconstruction with a knee tumor prosthesis, preceded and followed by three cytostatic cycles (Doxorubicin 75 mg∕m²). The HP examination has confirmed the previous diagnosis. The key microscopic features for the diagnosis of bone LMS was: malignant mesenchymal proliferation composed of intersecting fascicles of cells with eosinophilic, fibrillary cytoplasm and pleomorphic, elongated, blunt-ended, cigar-shaped nuclei of variable sizes; variable mitotic count; presence of tumor necrosis and stroma with changes that include hyalinization, myxoid change, with absence of chondroid or osteoid matrix; diffuse positivity for smooth muscle immunohistochemical markers: smooth muscle actin, desmin, h-caldesmon. At 12 months after the tumor resection, the patient is in good condition without any sign of local recurrence or metastatic disease. LMS represents a type of soft tissue sarcoma (STS), a variant of the spindle cell sarcomas, accounting for about 7% to 10% of all STS. Bone LMS can be primary or secondary; the primary variant is very rare, representing a very small percentage (around 0.7%) of all primary malignant bone tumors, according to the literature data. Very few cases are presented in the literature; the management of this kind of tumor is controversial, especially regarding the chemo- and radiotherapy.

Miscellaneous Tumours of Bone

There are several tumors that do not easily fit into the specific classifications of primary bone tumors. These tumors include tumors of neural, adipocytic, smooth muscle lineage, and some of uncertain lineage. The pathologic features with recent updates of these tumors are discussed here.

Rare bone sarcomas: A retrospective analysis of 145 adult patients from the French Sarcoma Group

The benefit of chemotherapy (CT) in rare bone sarcomas is not documented in prospective studies. Our retrospective study from the French sarcoma network for bone tumors ResOs was performed in adult patients (pts) from 1976 to 2014, with histologically verified diagnosis of leiomyosarcomas (LMS), undifferentiated pleomorphic sarcoma (UPS) or radiation-associated sarcomas of bone. The median follow-up was 4.7 years (95% CI: 3.7-6.5). Clinical features, treatment modalities and outcomes were recorded and analyzed from 145 pts (median age 53 years [range 20-87]). Site of disease was extremities (66%) or axial skeleton (34%), 111 (77%) presented with localized and potentially resectable disease. The most common histological subtypes were UPS (58%) and LMS (33%); 58% were high-grade tumors. Surgery was performed in 127 pts. In the 111 localized pts, 28 pts (25%) underwent upfront surgery or exclusive radiotherapy (RT; >50 Gy) without CT, whereas 83 pts (75%) received either neoadjuvant (n = 26) or adjuvant CT (n = 13) or both (n = 44). Neoadjuvant and adjuvant CT was mostly doxorubicin-based (95%/86%) and cisplatin-based (67%/63%). R0 resection was achieved in 59 pts, and a good histological response in 15 patients (25%). Adjuvant RT was performed in 24 (22%) pts. For the whole cohort (n = 145), the 5-year overall survival (OS) rate was 53% [42; 62]. In univariate analysis, age ≤ 60 was associated with a longer disease-free survival (DFS) (P = .0436). Neoadjuvant and adjuvant CT tended to be associated with better DFS (P = .056) with no significant impact on OS in this retrospective series.

Primary leiomyosarcoma of the distal tibia: A case report

The authors present an unusual case of a leiomyosarcoma of the distal tibia. Leiomyosarcoma tumors typically originate from smooth muscle tissue. It is rare for it to derive from bone and even rarer to be found in a bone of the lower limb. Given this extreme rarity in addition to nonspecific findings on plain film radiographs and magnetic resonance imaging (MRI), biopsy was needed in this case. It was only through immunochemistry staining that a definitive diagnosis was made. As such, this case is an illustrative example of an aggressive, though rare, primary lesion of the bone which should be considered in the differential diagnosis of a lytic intramedullary lesion. This case also highlights the need for careful evaluation of imaging features suggesting a potentially aggressive lesion requiring appropriate work up in a timely fashion.

The rare primary bone sarcomas: imaging-pathological correlation

Rare primary bone sarcomas are challenging entities both radiologically and pathologically. These include the diagnoses of spindle cell sarcoma (leiomyosarcoma, fibrosarcoma, synovial sarcoma, and malignant peripheral nerve sheath tumor), pleomorphic liposarcoma, and undifferentiated pleomorphic sarcoma. The radiographic and cross-sectional imaging features of each of these tumors are presented, along with current key pathological concepts. Frequently non-specific, the radiological appearances must be correlated with all clinical and pathological information available to enable an accurate diagnosis.

Comparison of clinicopathological features and outcomes in patients with primary leiomyosarcoma of bone and soft tissue

BACKGROUNDS AND OBJECTIVES

This investigation sought to describe the outcomes of primary leiomyosarcoma of bone (PLB) compared to soft tissue leiomyosarcoma (SLMS).

METHODS

This was a review of the Surveillance, Epidemiology, and End Results database from 1975 to 2016. Kaplan-Meier methods were used to estimate disease-specific survival (DSS), and a Cox regression model was used to identify prognostic factors.

RESULTS

Of the 7502 identifiable cases, 1% (n = 74) were PLB and 99% (n = 7428) were SLMS. Survival was the same between PLB and SLMS (p = .209). On multivariable analysis for high-grade SLMS, radiation (neoadjuvant: hazard ratio [HR], 0.56; 95% confidence interval [CI], 0.4-0.8; p = .003; adjuvant: HR, 0.75; 95% CI, 0.6-0.9; p = .008) and surgery (procedure specific) improved DSS. For PLB, wide resection/limb salvage (HR, 0.40; 95% CI, 0.3-0.5; p = .018) and amputation (HR, 0.69; 95% CI, 0.5-0.9; p < .001) were positive prognostic factors. Neither radiation nor chemotherapy were prognostic factors for survival in PLB.

CONCLUSIONS

For SLMS, radiation portends a survival advantage. For PLB, however, neither chemotherapy nor radiation were significant prognostic factors, which suggests the optimal treatment for PLB, similar to other primary soft tissue sarcomas originating in bone, remains an unmet medical need.

Unique presentation of palatal metastasis from high-grade spindle cell sarcoma of the bone

Spindle cell sarcoma (SCS) is a rare malignant tumour which can arise in bone and accounts for 2%-5% of primary bone cancer cases. Distant metastasis occurs predominantly in the lungs. However, metastasis to the soft palate, to the best of our knowledge, has never been previously reported. In this case report, we describe a unique presentation of soft palate metastasis in a patient with a history of high-grade SCS of the bone who presented with progressive dysphagia and nausea and vomiting who underwent surgical excision for palliation of symptoms.

Clinical outcomes of non-osteogenic, non-Ewing soft-tissue sarcoma of bone--experience of the Toronto Sarcoma Program

Non‐osteogenic, non‐Ewing soft‐tissue sarcoma (NONE‐STS) of bone is a rare presentation of primary bone cancers. Optimal treatments and outcomes for this heterogenous group are poorly described. We evaluated the factors associated with long‐term outcomes in patients with this disease. Patients with localized NONE‐STS of bone treated at the Toronto Sarcoma Program from 1987 to 2017 were identified. Clinical characteristics, treatment, and survival information were collected. Kaplan‐Meier (log‐rank) survival estimates from the time of definitive surgery, with uni‐/multivariate analyses (Cox) of sarcoma‐specific survival were performed. A total of 106 patients (60.4% male; median age 46 years) with NONE‐STS of bone were identified. Common histologies included undifferentiated pleomorphic sarcoma [UPS]/malignant fibrous histiocytoma [MFH] (UPS/MFH, 41.5%), leiomyosarcoma (LMS, 20.8%), and fibrosarcoma (FS, 11.3%). Tumors were often high grade (59.4%) and involved the extremities (88.7%), with most receiving chemotherapy (67.9%) with cisplatin/doxorubicin‐based regimens (73.6%). In the full cohort, 10‐year DFS (45.7%, [95%CI: 35.7‐55.8%]), OS (53.4%, [95%CI: 41.7‐62.2%]), and SSS (63.9%, [95%CI: 53.9‐72.5%]) were moderate. Histology specific, 10‐year SSS was 70.7% [95%CI: 56.1‐85.5%] for UPS/MFH, 51.8% [95%CI: 29.8‐73.8%] for LMS, and 72.2% [95%CI: 45.1‐99.2%] for FS. Only UPS/MFH (n = 4) showed sarcoma‐related death >10 years. Multivariate analysis identified axial location (HR = 35.5, [95%CI: 3.4‐369.6]), high grade (HR = 16.9, [95%CI: 1.6‐185.1]), and disease relapse (HR = 485.1, [95%CI: 36.3‐6482.6]) as risk factors for death (p < 0.05). Treatment with chemotherapy (HR = 0.1, [95%CI: 0.01‐0.86]) and necrosis ≥85% (HR = 0.2, [95%CI: 0.04‐0.99]) showed improved survival (p < 0.05). NONE‐STS of bone has favorable long‐term survival similar to osteosarcoma. Patients receiving chemotherapy derive benefit in retrospective analyses. UPS/MFH histologies show sarcoma‐related death beyond 10 years. Further data on histologic subgroups are needed.

Molecular differential diagnosis of uterine leiomyomas and leiomyosarcomas

Uterine leiomyomas (LM) and leiomyosarcomas (LMS) are considered biologically unrelated tumors due to their cytogenetic and molecular disparity. Yet, these tumors share morphological and molecular characteristics that cannot be differentiated through current clinical diagnostic tests, and thus cannot be definitively classified as benign or malignant until surgery. Newer approaches are needed for the identification of these tumors, as has been done for other tissues. The application of next generation sequencing enables the detection of new mutations that, when coupled to machine learning bioinformatic tools, advances our understanding of chromosomal instability. These approaches in the context of LM and LMS could allow the discovery of genetic variants and possible genomic markers. Additionally, the potential clinical utility of circulating cell-free tumor DNA could revolutionize the noninvasive detection and monitoring of these tumors. Here, we seek to provide a perspective on the molecular background of LM and LMS, recognizing their distinct molecular features that may lead to improved diagnosis and personalized treatments, which would have a measurable impact on women's reproductive health.

Primary Leiomyosarcoma of Bone: Review and Update

Context.—

Leiomyosarcoma of bone is a rare primary osseous sarcoma characterized by smooth muscle differentiation and absence of malignant osteoid formation. Leiomyosarcoma of bone is diagnostically challenging; this can be improved with greater awareness of this entity and the ability to differentiate it from its histologic mimics. Because of its rarity, only a small number of studies are available in the literature. These factors contribute to our limited understanding of its pathology, prognosis, and treatment.

Objective.—

To review the clinicopathologic features of leiomyosarcoma of bone and present the most up-to-date understanding of its behavior and management in accordance with the current literature.

Data Sources.—

Review of pertinent literature on the major features, current knowledge thereof, and the authors' experience in the diagnosis and management of leiomyosarcoma of bone.

Conclusions.—

Leiomyosarcoma of bone is a rare but well-recognized primary osseous sarcoma that may arise de novo or in association with radiation. Although it is diagnostically challenging, awareness of this rare sarcoma and knowledge of its key histomorphologic and immunohistochemical features allow for accurate diagnosis.

PRIMARY LEIOMYOSARCOMA OF BONE: CLINICOPATHOLOGIC AND PROGNOSTIC FACTORS ANALYSIS IN A SINGLE INSTITUTION

Objective

Primary leiomyosarcoma of bone (PLB) is a rare type of malignant bone tumor considered as a variant of the spindle cell sarcomas (SCS). The objective of this study was to analyze the clinicopathologic and the prognostic factors of patients with PLB treated at a single institution.

Methods

We retrospectively reviewed the records of 22 patients with pathologically confirmed PLB. The data collected were: age, sex, tumor size and location, grade and stage of the disease and histopathologic features. Mean age was 45.5 years (range, 17 to 73 y). Location was: upper limb (27.3%), lower limb (68.2%) and pelvis (4.5%). Patients had high grade in 90.9% of the reports. Margins were negative in 77.3% of the cases. Histological reports describe spindly sarcomatous cells arranged in fascicles with increased vascular formation without osteoid or chondroid matrix production. On immunohistochemistry, smooth muscle actin and desmin where positive in all cases.

Results

Mean follow-up time was 73.5 months (range, 5.3 to 331.1 m). We found 22.7% of local recurrence (LR). Distant metastasis (DM) was reported in 9 (40.9%) patients. Lung metastasis was the only DM affected site. Overall survival (OS) rate in 5 years was 59.1%. Predictors of OS were LR and DM.

Conclusions

PLB is an extremely rare malignant bone tumor that has a higher rate of DM and similar OS prognosis compared with other bone sarcomas. Level of Evidence IV, Case Series.

Clinical epidemiology and treatment outcomes of spindle cell non-osteogenic bone sarcomas - A nationwide population-based study

Purpose

To describe epidemiological and clinical characteristics, as well as long-term treatment outcomes of spindle cell non-osteogenic bone sarcomas (SCS), comprising leiomyosarcoma, fibrosarcoma and undifferentiated pleomorphic sarcoma in bone.

Method

We have analysed a nationwide cohort of 104 patients with histologically verified SCS diagnosed between 1975 and 2009, based on registry sources supplemented with clinical records from Norwegian hospitals involved in sarcoma management.

Results

In this unselected cohort, a stable annual incidence for SCS patients of slightly below 0.6 per million was observed, with a dominant peak among elderly patients. SCS is mostly a high-grade malignancy (92%) with a male to female ratio of 1.6 for all patients. The axial to appendicular ratio was 0.7, seemingly independent of age. More than one fourth of the patients (29%) had primary metastatic disease. Another 32 patients (46%) developed metastases during follow-up and 12 (17%) experienced local relapses. The five-year sarcoma-specific survival rate was 37%, with no documented improvement over time. Primary metastatic disease was an adverse prognostic factor for survival. Predisposing factors were documented in 19 patients (18%). Negative prognostic factors for overall survival were tumour size >9 cm, age > 40 years, axial tumour localization, FS as subtype and pathologic fracture at time of diagnoses. As expected, patients who received both surgery and chemotherapy as their primary treatment for high-grade SCS (25%) significantly had best sarcoma specific five years survival (62%).

Conclusion

We confirm SCS as a rare high-grade bone sarcoma entity, mostly among elderly patients and with a poor overall outcome. The combined treatment of surgery and chemotherapy is essential to achieve optimal long-term survival of SCS.

Establishment and characterization of patient-derived xenograft and its cell line of primary leiomyosarcoma of bone

Primary leiomyosarcoma (LMS) of bone is a rare and aggressive mesenchymal malignancy that differentiates toward smooth muscle. Complete resection is the only curable treatment, and novel therapeutic approaches for primary LMS of bone have long been desired. Patient-derived xenografts (PDXs) and cell lines are invaluable tools for preclinical studies. Here, we established PDXs from a patient with primary LMS of bone and a cell line from an established PDX. Bone primary LMS tissue was subcutaneously implanted into highly immune-deficient mice. After two passages, a piece of the tumor was subjected to tissue culturing, and a morphological evaluation and proteomic analysis were performed on the PDX and the established cell line. Moreover, the responses of the established cell line to anti-cancer drugs were examined. Microscopic observations revealed that the PDX tumors retained their original histology. The cell line was established from the third-generation PDX and named NCC-LMS1-X3-C1. The cells were maintained for over 18 mo and 40 passages. The cells exhibited a spindle shape and aggressive growth. Mass spectrometric protein identification revealed that the original tumor tissue, PDX tumor tissue, and NCC-LMS1-X3-C1 cells had similar but distinct protein expression profiles. We previously established the cell line, NCC-LMS1-C1, from the tumor tissue of same patient. We found that the response to drug treatments was different between NCC-LMS1-X3-C1 and NCC-LMS1-C1, suggesting the heterogeneous traits of tumor cells in the identical tumor tissue. This set of PDXs and stable cell line will be a useful resource for bone LMS research.

Denosumab as a potential therapeutic option for leiomyosarcoma with osteoclast-like giant cells: A case report

Bone leiomyosarcoma is a rare primary osseous malignant tumor with a high metastatic potential. Similar to other bone sarcomas, high histological grade and tumor stage are predictive of a poor outcome. We herein present our experience with treating a 64-year-old woman with bone leiomyosarcoma accompanied by multiple bone metastases. A biopsy revealed occasional osteoclast-like giant cells. In addition to radiation therapy, the osteoclastogenesis inhibitor denosumab was administered but the patient did not undergo adjuvant chemotherapy or surgery. Good clinical and short-term radiological responses to denosumab have been observed for 2 years. Therefore, denosumab may represent a viable treatment option without the need for adjuvant chemotherapy.

Establishment and proteomic characterization of NCC-LMS1-C1, a novel cell line of primary leiomyosarcoma of the bone

Background

Leiomyosarcoma (LMS) is one of most aggressive mesenchymal malignancies that differentiate towards smooth muscle. The clinical outcome of LMS patients is poor; as such, there is an urgent need for novel therapeutic approaches. Experimental models such as patient-derived cell lines are invaluable tools for pre-clinical studies. In the present study, we established a stable cell line from the tumor tissue of a patient with a primary LMS of the bone. Despite the urgent need for novel therapeutic strategies in LMS, there are only a few LMS cell lines available in public cell banks, none of which are primary to the bone.

Methods

Bone primary LMS tumor tissues were sampled to establish cell lines. Morphological and proteomic analyses were performed and sensitivity to pazopanib was evaluated.

Results

NCC-LMS1-C1 cells were maintained for over 100 passages. The cells exhibited a spindle shape and aggressive growth; they also expressed smooth muscle actin, reflecting the original LMS tissue (i.e. smooth muscle cells). The cells also showed tumor characteristics such as colony formation on soft agar and sensitivity to pazopanib, doxorubicin and cisplatin, with half-maximal inhibitory concentrations of 4.5, 0.11 and 20 μM, respectively. Proteomic analyses by mass spectrometry and antibody array revealed some differences in the protein expression profiles of these cells as compared to the original tumor tissue.

Conclusions

Our results indicate that the NCC-LMS1-C1 cell lines will be useful for LMS research.

Expression and role of TYRO3 and AXL as potential therapeutical targets in leiomyosarcoma

Background:

Leiomyosarcoma (LMS) are 15% of adult sarcomas and remain seldom curable in metastatic phase. The TAM receptors and their ligands are overexpressed or activated in multiple malignancies, including LMS.

Methods:

The TAM receptor and ligand expression was evaluated in LMS cell lines and 358 sarcoma samples by either gene expression or immunohistochemistry. TYRO3 and AXL were knocked down. Crizotinib and foretinib were investigated in vitro.

Results:

High expression of TYRO3 and AXL was detected in LMS cell lines. TYRO3 or AXL gene knockdown reduced cell proliferation/colony formation. Crizotinib and foretinib decreased TYRO3 and AXL phosphorylation, apoptosis, G2/arrest and reduced colony formation. Immunohistochemistry performed in 107 sarcomas showed higher expression of TYRO3 and GAS6 in LMS vs other sarcomas and nuclear TYRO3 only in LMS. Microarray gene expression performed in 251 sarcomas revealed significantly higher expression of TYRO3 and GAS6 in LMS than other sarcomas. Leiomyosarcoma patients with high expression of GAS6 or PROS1 present a significantly worse PFS.

Conclusions:

Leiomyosarcoma patients, especially those whom develop metastasis, express higher levels of TYRO3 and GAS6. Crizotinib and foretinib showed effective antitumour activity in LMS through TYRO3 and AXL deactivation indicating that clinical trials using TYRO3 and AXL inhibitors are warranted in advanced LMS.

Soft Tissue Tumors Rarely Presenting Primary in Bone; Diagnostic Pitfalls

Primary bone sarcomas represent extremely rare entities. The use of now abolished labels, such as malignant fibrous histiocytoma and hemangiopericytoma, has significantly hampered the chance of identifying specific entities. It is now accepted that a broad variety of mesenchymal malignancies most often arising on the soft tissue may actually present as primary bone lesions. A more accurate morphologic partition is justified based on availability of distinct therapeutic options. An integrated diagnostic approach represents the only way to achieve a correct classification. In consideration of the significant complexity, primary bone sarcomas should ideally be handled in the context of expert centers.

[Lymph node metastasis of osteosarcomas]

Lymph node metastasis of osteosarcomas is a rather rare phenomenon; according to different authors, the incidence of lymph node metastasis is 4 to 11%. The detection of lymph node metastases in osteosarcoma is associated with a significant reduction in the 5-year survival of patients and allows its classification as clinical stage IV tumor. The risk factors for lymph node metastases in patients with bone sarcomas are age (≥64 years), gender (female), nosological entity (undifferentiated pleomorphic sarcoma, osteosarcoma, chondrosarcoma), tumor depth (muscle, bone), and the size of primary tumor (>5 сm). The mechanism of lymph node metastasis of osteosarcomas seems to be related to mesenchymal-to-epithelial transition.

Prognostic Differences: Epstein-Barr Virus-Associated Primary Leiomyosarcoma of the Spine Versus Spinal Leiomyosarcoma Metastases

OBJECTIVE

The authors studied 6 cases of osseous leiomyosarcoma of the spine. Two of these cases were of immunocompromised human immunodeficiency virus (HIV)-positive patients with Epstein-Barr virus (EBV)-associated primary vertebral leiomyosarcomas. The remaining 4 cases were of patients with leiomyosarcoma metastases to the spine.

METHODS

Each patient underwent surgical resection of their vertebral mass; however, the patients with the EBV-associated tumors had the best postoperative prognosis.

RESULTS

The HIV-positive patients have had no further local recurrence, while the other 4 patients had rapid local recurrences requiring multiple surgical interventions. Furthermore, the patients living with HIV have lived longer with fewer leiomyosarcoma-related health complications.

CONCLUSIONS

These findings suggest that EBV-associated vertebral leiomyosarcoma is of a less aggressive variety than metastatic leiomyosarcoma of the spine.

Metatarsal leiomyosarcoma masquerading as acute osteomyelitis - A diagnostic trap unveiled by vigilant clinical, radiologic and pathologic analysis

Due to overlapping clinical and radiological features, the differentiation between osteomyelitis and bone tumor can be challenging. A 48-year-old lady presented with intermittent left foot pain for a few months. Plain radiographs showed an osteolytic lesion affecting the proximal diaphysis of the left fourth metatarsal bone, with thinning and irregularities of the cortex and focal periosteal reaction. Ultrasonography revealed diffuse subcutaneous edema in the dorsum of the left foot, cortical irregularities along the mid-shaft of the left fourth metatarsal bone, and surrounding periosteal collection. Computed tomography showed medullary expansion along the shaft and base of the left fourth metatarsal bone with cortical irregularities and defects suggestive of cloaca, and focal mild periosteal new bone formation. The clinico-radiologic diagnosis was acute osteomyelitis with periosteal collection. During open biopsy, the finding of intramedullary fleshy tissue in the absence of significant inflammatory edema and purulent discharge, and subsequent negative culture result prompted a review of the histologic slides which was initially reported as benign fibroblastic tissue proliferation. Careful analysis of the histomorphology disclosed a spindle cell sarcoma for which ray amputation of the fourth and fifth metatarsal was performed. The final diagnosis was grade 1 leiomyosarcoma and the patient remained well 33 months after the operation.

UK guidelines for the management of bone sarcomas

This document is an update of the British Sarcoma Group guidelines published in 2010. The aim is to provide a reference standard for the clinical care of patients in the UK with bone sarcomas. Recent recommendations by the European Society of Medical Oncology, The National Comprehensive Cancer Network and The National Institute for Health and Care Excellence have been incorporated, and the literature since 2010 reviewed. The standards represent a consensus amongst British Sarcoma Group members in 2015. It is acknowledged that these guidelines will need further updates as care evolves. The key recommendations are that bone pain or a palpable mass should always lead to further investigation and that patients with clinico-radiological findings suggestive of a primary bone tumour at any site in the skeleton should be referred to a specialist centre and managed by a fully accredited bone sarcoma multidisciplinary team. Treatment recommendations are provided for the major tumour types and for localised, metastatic and recurrent disease. Follow up schedules are suggested.

Distal ulna leiomyosarcoma treated with custom polymethylmethacrylate prosthesis with a 4-year follow-up

BACKGROUND

Intraosseous leiomyosarcoma is a rare neoplasm having an aggressive biologic behavior. The distal end of the ulna is a very uncommon site for this type of primary bone tumor frequently mistaken for benign lesions. En bloc resection of the distal ulna with reconstruction is a valid option as a limb salvage procedure for the treatment of this difficult problem, minimizing local recurrence while preserving hand function.

CASE DESCRIPTION

We present an unusual case of a 63-year-old woman with a primary leiomyosarcoma arising from the distal end of the ulna treated successfully with a wide excision and custom distal ulna, with 4-year follow-up and no recurrence.

LITERATURE REVIEW

Tumors to develop at the distal end of the ulna have been reported as part of large series such as Dahlin and few case reports. According to Cooney, Exner, and Mankin, reconstruction for distal ulnar neoplasms is not necessary to maintain function. However, Noble and Laurentin-Perez disagree because stabilization of the distal ulna following large resection, as in our case, can be a significant problem with associated pain and weakness due to a decreased interosseous space with ulnar stump impingement on the radial metaphysis and ulnar translation of the carpus.

CLINICAL RELEVANCE

Custom methacrylate in situ radioulnar joint prosthesis for reconstruction of a large segment of the distal ulna can be a valid option to reestablish the mechanical continuity of the forearm, reducing pain and improving strength and function.

MRI, MDCT features, and clinical outcome of extremity leiomyosarcomas: experience in 47 patients

OBJECTIVE

To describe MRI, MDCT features, and clinical outcome of extremity leiomyosarcomas (LMS).

MATERIALS AND METHODS

In this IRB-approved, HIPAA-compliant retrospective study, we included 47 patients (23 women, 24 men; mean age: 55.3 years, range: 17-85 years) with pathologically confirmed extremity LMS seen at our adult tertiary cancer center between 2000 and 2012. MRI/MDCT of primary tumors in 23 patients and follow-up in all patients were reviewed by two radiologists in consensus. Clinical data were extracted from electronic medical records.

RESULTS

Primary tumors were distributed in bones (6 out of 47), deep soft tissues (24 out of 47), and superficial soft tissues (17 out of 47). On imaging (bone = 4, deep soft tissue = 11, superficial soft tissue = 8), compared with skeletal muscle, they were T1 iso-hypointense and T2 hyperintense. Bone LMS were metaphyseal tumors with cortical destruction (3 out of 4). Deep soft-tissue LMS were large with hemorrhage (7 out of 11) and necrosis (10 out of 11). Superficial soft-tissue LMS were relatively smaller, homogeneously enhancing (6 out of 8) tumors. Distant metastases developed in 32 out of 47 patients (bone LMS [6 out of 6], deep soft-tissue LMS [18 out of 24], superficial soft-tissue LMS [8 out of 17]), commonly to lung (29 out of 47) and bone (14 out of 47). At the time of writing, 22 out of 36 patients (bone LMS [4 out of 6], deep soft-tissue LMS [15 out of 24], superficial soft-tissue LMS [4 out of 17]) have died. There was no statistically significant correlation between metastatic disease and tumor size or grade.

CONCLUSION

Extremity LMS arise in bones and in the deep and superficial soft tissues, frequently metastasize to the lungs, and have a poor prognosis. Superficial LMS tend to have a better prognosis than bone or deep soft-tissue LMS.