Primary leiomyosarcoma of bone: a clinicopathologic, immunohistochemical, and ultrastructural study of 33 patients and a literature review

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.

Kinase fusion positive intra-osseous spindle cell tumors: A series of eight cases with review of the literature

Mesenchymal spindle cell tumors with kinase fusions, often presenting in superficial or deep soft tissue locations, may rarely occur in bone. Herein, we describe the clinicopathologic and molecular data of eight bone tumors characterized by various kinase fusions from our files and incorporate the findings with the previously reported seven cases, mainly as single case reports. In the current series all but one of the patients were young children or teenagers, with an age range from newborn to 59 years (mean 19 years). Most tumors (n = 5) presented in the head and neck area (skull base, mastoid, maxilla, and mandible), and remaining three in the tibia, pelvic bone, and chest wall. The fusions included NTRK1 (n = 3), RET (n = 2), NTRK3 (n = 2), and BRAF (n = 1). In the combined series (n = 15), most tumors (73%) occurred in children and young adults (<30 years) and showed a predilection for jaw and skull bones (40%), followed by long and small tubular bones (33%). The fusions spanned a large spectrum of kinase genes, including in descending order NTRK3 (n = 6), NTRK1 (n = 4), RET (n = 2), BRAF (n = 2), and RAF1 (n = 1). All fusions confirmed by targeted RNA sequencing were in-frame and retained the kinase domain within the fusion oncoprotein. Similar to the soft tissue counterparts, most NTRK3-positive bone tumors in this series showed high-grade morphology (5/6), whereas the majority of NTRK1 tumors were low-grade (3/4). Notably, all four tumors presenting in the elderly were high-grade spindle cell sarcomas, with adult fibrosarcoma (FS)-like, malignant peripheral nerve sheath tumor (MPNST)-like and MPNST phenotypes. Overall, 10 tumors had high-grade morphology, ranging from infantile and adult-types FS, MPNST-like, and MPNST, whereas five showed benign/low-grade histology (MPNST-like and myxoma-like). Immunohistochemically (IHC), S100 and CD34 positivity was noted in 57% and 50%, respectively, while co-expression of S100 and CD34 in 43% of cases. One-third of tumors (4 high grade and the myxoma-like) were negative for both S100 and CD34. IHC for Pan-TRK was positive in all eight NTRK-fusion positive tumors tested and negative in two tumors with other kinase fusions. Clinical follow-up was too limited to allow general conclusions.

Primary leiomyosarcoma of the small finger treated with ray amputation: A case report

INTRODUCTION

Malignant sarcomas of the upper extremity are rare tumors that can have an overwhelming impact on a patient's function, quality of life, and life expectancy. Rarer still is the malignant tumor of the hand or digits, which represent an incredibly small percentage of upper extremity tumors. This paucity of cases can lead to difficult decision making and treatment options that may not always have clearly established results and outcomes.

CASE

In this case, we present a young, otherwise healthy patient that was diagnosed with a primary leiomyosarcoma of the small finger. After her diagnosis, she underwent extensive oncologic workup, and subsequently underwent successful ray amputation with an excellent outcome. She remains disease free.

DISCUSSION

Leiomyosarcoma is a malignant cancer that can be troublesome to diagnose in the extremities, as it is usually found in the smooth muscle of organs and the pelvis. Local control of the tumor is critical to successful, disease free treatment. Good functional and clinical outcomes can be attained with ray amputation, as seen in this patient.

CONCLUSION

This case demonstrates a successful treatment approach to the patient with a primary malignant soft tissue sarcoma who was treated with a ray amputation. The clinician and surgeon must maintain a high index of suspicion of soft tissue malignancies, as a prompt diagnosis and treatment is critical to a good outcome and survival.

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 leiomyosarcoma of the spine: an analysis of imaging manifestations and clinicopathological findings

BACKGROUND

Primary leiomyosarcoma of the spine is extremely rare and lacks specific clinical symptoms. This study investigated the imaging manifestations and clinicopathological findings of primary leiomyosarcoma of the spine, aiming to improve the radiologists' understanding of the disease and reduce misdiagnoses.

METHODS

The clinical, imaging, and pathological manifestations in eleven patients with pathologically confirmed primary leiomyosarcoma of the spine were retrospectively analyzed. The imaging features analyzed included lesion location, shape, border, size, and density/intensity, and adjacent bone destruction status, residual bone trabeculae, vertebral compression, and contrast enhancement.

RESULTS

The patients' primary clinical symptom was usually focal pain. Primary leiomyosarcoma of the spine was mostly a solitary lesion and tended to occur in the posterior elements. The tumors had a lobulated shape with osteolytic bone destruction, ill-defined borders, and could involve multiple segments. Computed tomography (CT) examination showed isodense masses. Six patients showed residual bone trabeculae. Two patients had miscellany T2-weighted imaging (T2WI) signals, while the tumor and spinal cord of the remaining patients were isointense on T1-weighted imaging (T1WI) and T2WI. Among the seven patients who underwent contrast-enhanced scanning, six displayed homogeneous enhancement. Eight patients underwent gross-total tumor resection with no recurrence.

CONCLUSIONS

Primary leiomyosarcoma of the spine tends to be a solitary lesion in the posterior elements and appears as a lobulated mass with osteolytic bone destruction and an ill-defined border. The tumor and spinal cord can be isointense on T1WI and T2WI. Contrast-enhanced scanning displays homogeneous enhancement. The lesion tends not to recur after surgical gross-total tumor resection.

Pre-surgical management of primary leiomyosarcoma of the bone

"Leiomyosarcoma is a rare type of smooth muscle cell tumor, with an incidence of 7-10% compared to other types of sarcomas. It develops primarily in the retroperitoneal cavity, the genital tract and extremities. Leiomyosarcoma can also affect the bone, either as a primary tumor or as metastasis. Primary osseus leiomyosarcoma is a rare finding in patients with radiologically identified osteolytic lesions having an incidence of <1% of total primary bone tumors.Due to its low incidence patients with primary osseous leiomyosarcoma are never diagnosed before immunohistochemical analysis and case management is difficult because of the lack of specific indications pertaining to primary osseus leiomyosarcoma. Data on age specific incidence is scarce but there seems to be a tendency towards a higher incidence with advanced age. The purpose of this work is to discuss the complete management of primary osseus leiomyosarcomas based on interdisciplinary medical teams’ indications in a Romanian hospital setting"

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.

Comparison of clinical features and outcomes of patients with leiomyosarcoma of bone and soft tissue: a population-based cohort study

BACKGROUND

Leiomyosarcoma commonly occurs in soft tissue but rarely in the bone. Whether leiomyosarcoma of bone and soft tissue have similar clinical characteristics and outcomes remains unknown.

METHODS

This retrospective analysis was based on data from the Bone and Soft Tissue Tumor Registry in Japan. Patients with leiomyosarcoma of bone and soft tissue were enrolled. Overall survival and distant metastasis-free survival were estimated using the Kaplan-Meier method, and the Cox regression model was used to identify the prognostic factors.

RESULTS

A total of 888 patients (60 leiomyosarcoma of bone and 828 leiomyosarcoma of soft tissue) were included in the study. Clinical characteristics were similar between the two groups, except for younger age in leiomyosarcoma of bone than in leiomyosarcoma of soft tissue (median 56 years vs. 66 years, P < 0.0001). To evaluate the prognostic factors and efficacy of adjuvant chemotherapy, data of localized and locally curative cases were extracted (total 572: 33 leiomyosarcoma of bone and 539 leiomyosarcoma of soft tissue). The 5-year overall survival rates of leiomyosarcoma of bone and soft tissue patients were similar (63.8% vs. 75.2%, P = 0.43); the 5-year distant metastasis-free survival tended to be worse in leiomyosarcoma of bone than in leiomyosarcoma of soft tissue (37.4% vs. 57.9%, P = 0.28). Larger tumor size (≥5 cm) and older age (≥65 years) correlated with poor overall survival in leiomyosarcoma of soft tissue patients. Adjuvant chemotherapy tended to prolong the overall survival of both leiomyosarcoma of bone (P = 0.11) and leiomyosarcoma of soft tissue patients with tumor size >10 cm (P = 0.06).

CONCLUSIONS

The clinical characteristics and outcomes of leiomyosarcoma of bone and soft tissue patients were similar. In localized cases, adjuvant chemotherapy may improve the survival of leiomyosarcoma of bone and soft tissue patients with large-size tumor.

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.

The 'other' bone sarcomas in Japan: a retrospective study of primary bone sarcomas other than osteosarcoma, Ewing sarcoma and chondrosarcoma, using data from the Bone Tumuor Registry in Japan

BACKGROUND

To date, no standard treatments for primary bone sarcomas other than those for osteosarcoma, Ewing sarcoma and chondrosarcoma have been developed.

METHODS

The clinical characteristics and prognostic factors of 330 patients with primary bone sarcomas other than osteosarcoma, Ewing sarcoma and chondrosarcoma, listed in a nationwide tumour registry (Bone and Soft Tissue Tumor Registry in Japan) were investigated. The effects of adjuvant chemotherapy were determined by comparing the outcomes of patients with non-metastatic bone tumours who received surgery plus chemotherapy with those of patients who underwent surgery alone.

RESULTS

The most common diagnosis was undifferentiated high-grade pleomorphic sarcoma. Axial site tumours (47.8%) and distant metastases at presentation (24.5%) were frequent. The 5-year overall and progression-free survival rates were 44.9 and 39.9%, respectively. Prognostic factor analysis identified surgery as an independent predictor of overall survival, and distant metastases at presentation was significant and independent predictor of both overall and progression-free survival. No significant difference in outcome was observed between patients treated with surgery alone and those treated with surgery plus chemotherapy (P = 0.71).

CONCLUSIONS

Patients with bone sarcomas other than osteosarcoma, Ewing sarcoma and chondrosarcoma without metastasis at presentation have a relatively good prognosis with definitive surgery; however, the benefit of adjuvant chemotherapy is unclear.

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.

Rare Primary Malignant Bone Sarcomas

Simple Summary

Primary malignant bone tumors are infrequent cancers. More than 90% of these neoplasms are classified as osteosarcomas, Ewing sarcomas or chondrosarcomas, and their clinical presentation, diagnosis, and treatment principles are well-established. The entities described in this article, are ultra-rare varieties of bone sarcomas, and there clinical and histological characteristics are not well known. Therefore, they are very difficult to be diagnosed and there is a lot of uncertainty on their treatment. Because of their rarity, it is also extremely difficult to perform clinical research on these cancers. This article creates more awareness of these very rare bone tumors. It explains how to recognize and diagnose each entity and it summarizes the medical scientific literature that is available on these cancers. Increasing awareness and clinical research for these cancers are key elements to improve the prognosis for patients with these diseases in the long term.

Abstract

Rare primary malignant bone sarcomas (RPMBS), other than osteosarcoma, chondrosarcoma, chordoma, and Ewing sarcoma, account for about 5–10% of primary bone tumors and represent a major diagnostic challenge. These tumors include spindle cell and round cell sarcoma entities, hemangiopericytoma-like and vascular tumors. Additionally, several histotypes, traditionally described in the soft tissues, such as myxofibrosarcoma, synovial sarcoma, and malignant peripheral nerve sheath tumor of bone, have been reported in patients with primary bone tumors. While wide surgical resection is the mainstay of local treatment, systemic therapy of these rare entities is controversial. Patients with undifferentiated spindle cell or pleomorphic high-grade tumors of bone, are usually treated with osteosarcoma-like chemotherapy, while patients with round cell and undifferentiated round cell tumors (URCTs), may respond to sarcoma treatment regimens for Ewing sarcoma patients. Studies on analogies and differences among these ultra-rare tumors have seldom been reported. This review describes relevance, clinical aspects, diagnostic procedures, staging, treatment recommendations, and current research in this composite tumor group.

Two Cases of Intraosseous Pseudomyogenic (Epithelioid Sarcoma-Like) Hemangioendothelioma With Unusual Features, Expanding the Clinicopathological Spectrum

Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma (PMHE) is a distinct vascular neoplasm mostly observed in the lower extremities of young adults with characteristic histopathological features. In this article, we present 2 unusual cases of PMHE. Case 1: A 28-year-old male presented with pain and stiffness in his left shoulder. Radiologic examination revealed an expansile, lytic, heterogeneously enhancing, destructive lesion in his left scapula, along with multiple avid marrow lesions in his other bones. Biopsy revealed a cellular tumor composed of plump spindly and epithelioid cells arranged in fascicles and focally, in clusters, admixed with neutrophils and histiocytes, with interspersed many osteoclast-like giant cells and reactive bone. Case 2: A 63-year-old male presented pain and swelling in his right middle finger, with no other lesion elsewhere in his body. Radiologic imaging disclosed a 1.5-cm-sized lobulated, expansile, lytic, destructive lesion in the distal end of the third metacarpal bone of his right hand. Biopsy examination revealed a cellular spindle cell tumor, composed of plump spindly cells, arranged in fascicles, including "tadpole-like" or "strap-like" cells and interspersed inflammatory cells. Immunohistochemically, tumor cells in both cases were positive for AE1/AE3, CD31, and Fli1, while negative for desmin and CD34. INI11 was retained. The presented cases of PMHE, occurring at unusual locations, in an older individual in the second case, along with variable histopathological features, noted in the first case, seem to expand the clinicopathological spectrum of these uncommon neoplasms. Differential diagnoses and review of similar cases are presented.

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.

Leiomyogenic tumor of the spine: surgical treatments and long-term outcomes of 12 consecutive patients

OBJECTIVE

Leiomyogenic tumor of the spine is rare with limited published information. Here, the authors report the clinical features and long-term surgical outcomes and investigate the prognostic factors affecting disease-free survival (DFS).

METHODS

Twelve patients presented to the authors' institution for surgical treatment from January 2005 to December 2018. The clinical characteristics and outcomes were retrospectively reviewed, and the DFS rate was estimated using the Kaplan-Meier method. The log-rank test was used to identify the potential prognostic factors, with p < 0.05 considered statistically significant.

RESULTS

The mean patient age was 49.7 ± 12.9 years (range 22-73 years). Four patients underwent marginal en bloc resection, and 8 patients underwent conventional piecemeal resection. Pathological diagnosis revealed leiomyosarcoma in 9 patients and leiomyoma in 3 patients. Three patients had tumor recurrence at a mean follow-up of 10.4 months (range 7.0-15.0 months), while 4 developed metastases at an average of 13.8 months (range 5.5-21.3 months) postoperatively. During the mean follow-up of 33.7 months (range 9.6-78.5 months), the estimated 1- and 5-year DFS rates were 66.7% and 38.2%, respectively. Albumin loss > 20 g/L after surgery, Ki-67 positivity > 10%, and piecemeal resection were correlated with worse DFS.

CONCLUSIONS

Surgical management of spinal leiomyogenic tumors is challenging due to the high rate of recurrence and metastases. En bloc resection should be performed in eligible patients. Albumin loss > 20 g/L and the Ki-67 index may be independent factors affecting prognosis.

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.

Primary oral leiomyosarcoma: A systematic review and update

The aim of this systematic review was to address the clinicopathologic inconsistencies noted with primary oral leiomyosarcoma in the literature by amassing the available data published into a comprehensive analysis. Eligibility criteria included publications of cases with dedicated immunohistochemical work-up along with radiographs to evaluate location. Based on these criteria, the systematic review compiled 29 cases. Four primary location sites were identified in the reported cases: soft tissue presentation only, soft tissue with bony involvement, bony involvement only, and bony involvement with a soft tissue component. The majority of primary oral leiomyosarcoma cases reviewed showed a soft tissue predilection, which is in contrast to prior reports of jawbones being the most common site. In addition, there was an improved 5-year survival rate for primary oral leiomyosarcoma limited to the oral cavity and gnathic bones without extension into paranasal sinuses.

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.

A Spindle Cell Tumor of Unknown Origin and Diffuse Bone Marrow Involvement in a Patient with Hypercalcemia

Background

Metastasis of unknown origin in bone marrow is infrequent, although, when it occurs, adenocarcinoma is the most common histologic type. Involvement of bone marrow by a spindle cell tumor and presentation with hypercalcemia are very rare.

Method

This report describes a 21-year-old man with diffuse bone marrow involvement from a spindle cell tumor.

Results

The patient presented with low back pain, anemia, thrombocytopenia, azotemia, and hypercalcemia. Bone marrow biopsy revealed a spindle cell tumor that was positive for vimentin staining but whose primary site could not be identified. A bone marrow scan revealed absence of uptake, which suggested systemic disease. We treated this case as a type of sarcoma by giving combined chemotherapy consisting of vincristine, actinomycin-D and cyclophosphamide. The patient showed a clinical response for seven months, but the disease progressed despite chemotherapy and he died one year after diagnosis.

Conclusions

We have documented a rare case of spindle cell tumor involving bone marrow without evidence of the tumor's primary site.

Primary leiomyosarcoma of the distal fibula: A case report and review of the literature

We describe a primary leiomyosarcoma of bone located in the distal fibula in a 67- year-old man. Plain radiographs and computer tomography scan revealed a lytic destructive lesion in the distal metaepiphyseal region of the left fibula with little involvement of the surrounding soft tissues. The lesion was composed of proliferating spindle-shaped cells with very slim cytoplasm and narrow oval cigar shaped nuclei. Immunohistochemistry studies demonstrated a strong positivity for actin and desmin, and weak positivity for caldesmon.

Primary leiomyosarcoma of the spine treated with total en bloc spondylectomy: the first case in Thailand-a case report and literature review

Leiomyosarcoma is a rare type of malignant soft tissue tumor and also one of the most aggressive soft tissue sarcomas. It commonly occurs in uterus, abdominal viscera, retroperitoneal space and soft tissue of the extremities. Primary osseous leiomyosarcoma is a rare condition. Furthermore, primary leiomyosarcoma of the spine is extremely rare. Only few cases have been reported. However, the treatment and outcomes remains controversial. Therefore, the objective of this case report is to illustrate the management of this extremely rare disease by using total en bloc spondylectomy (TES) procedure, which is one of a suitable option for surgical resection of the spinal tumors. In this study, we presented an unusual case of a 61-year-old female, who was diagnosed as primary leiomyosarcoma of the twelfth thoracic spine with liver metastasis, treated with total en bloc spondylectomy of the twelfth thoracic vertebra followed by chemotherapy. On last follow-up, 6 months after the surgery, the clinical outcome remained in good condition and no signs of local recurrence. In conclusion, primary leiomyosarcoma of the spine is an extremely rare and difficult to diagnosis. Immunohistochemistry studies are very important for confirmation of the diagnosis. Standard treatment remains controversial. However, surgical resection is still treatment of choice. One of the most effective surgical options is TES, which give the better outcome and minimize local recurrence, if indicate.

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.

Primary leiomyosarcoma of the bone: a case report and a review of the literature

RATIONALE

Leiomyosarcoma (LMS) is a malignant sarcoma that can occur in different anatomic sites, including the bone, showing similar histological characteristics but heterogeneous clinical behavior and prognosis. Primary bone LMS was first described in 1965. It is a very rare sarcoma, accounting for <0.7% of all primary malignant bone tumors.

PATIENT CONCERNS

We report the case of a 52-year-old male with primary bone LMS who presented with a solitary osteolytic lesion with focal cortical destruction in the left clavicle, seen on an x-ray and subsequent computed tomography (CT) scan.

DIAGNOSIS

The multidisciplinary Osteoncology team of our institute planned a biopsy that revealed the presence of spindle and pleomorphic cells with a positive reaction for smooth muscle actin and desmin at immunohistochemical analysis, without the presence of cartilage or bone matrix. These results were consistent with a high-grade malignant LMS arising from the bone.

INTERVENTIONS

Complete surgical resection of the tumor was performed and a decision was made with the patient not to proceed with adjuvant chemotherapy or radiotherapy.

OUTCOMES

After more than 1 year of surgery, the patient is well, with no evidence of recurrent or metastatic disease. Follow-up is ongoing.

LESSONS

Little is known about the biology and clinical behavior of bone LMS due to its extreme rarity. A multidisciplinary team in a specialized center is needed for the optimal management of the disease. Surgery with a curative intent is the cornerstone of treatment of localized disease. No data are available about chemotherapy in neoadjuvant, adjuvant, or advanced settings. Further research is needed to identify more effective therapies.

Free disease long-term survival in primary thoracic spine leiomyosarcoma after total en bloc spondylectomy: A case report

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Primary vertebral leiomyosarcoma in thoracic spine is extremely rare.

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Metastatic origin must be excluded.

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Wide surgical excision can result in local tumor control and long-term survival.

Introduction

To describe an unusual primary vertebral leiomyosarcoma in thoracic spine.

Presentation of case

An isolated lesion of the T11 vertebra in a 62-year-old woman with no neurologic deficit is reported. Imaging findings indicated a nonspecific high-grade malignant lesion. TC-guided biopsy failed thus open incisional biopsy was needed. A diagnosis of low-intermediate mesenchymal sarcoma was made. A total en bloc spondylectomy of T11 was performed with three-column reconstruction. The histology and immunostaining showed the appearance of leiomyosarcoma. After diagnosis, post-operative radiation therapy was performed. Metastatic lesion was ruled out by CT scans of the chest, abdomen and pelvis, in addition to total body radionuclide scanning and 18-F-FDG-PET. After five years of follow-up, no signs of local recurrence, metastasis or distant lesions suggesting a primary lesion were observed.

Discussion

Vertebral primary leiomyosarcoma is exceedingly rare. Primary vertebral leiomyosarcoma diagnosis must be performed when the metastatic origin is excluded. For the treatment of primary tumors, total en bloc spondylectomy (TES) is the technique of choice to achieve marginal or wide tumor resection, decrease the risk of local recurrence and remote lesions and increase survival.

Conclusions

A well-planned pre-operative study and a wide surgical excision can result in local tumor control and long-term survival. This case presents the longest disease-free survival period of a primary leiomyosarcoma in spinal location after total en bloc spondylectomy.

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.

Primary vertebral leiomyosarcoma masquerading as a nerve sheath tumour

A 47-year-old woman presented with symptoms of low back pain and weakness in bilateral lower limbs. MRI of the spine revealed a mass arising from T11 vertebra involving neural foramina at bilateral T11-12 and right T10-11 levels with extension to the right paravertebral region. Suspecting a nerve sheath tumour, she underwent posterior spinal decompression, stabilisation and debulking, following which her neurological symptoms resolved. Histopathological and immunohistochemical evaluation revealed a leiomyosarcoma. A month later she developed sudden paraparesis and MRI revealed an increase in size of the tumour with cord compression and displacement. She underwent a repeat spinal decompression and debulking procedure after which she received adjuvant radiotherapy via volumetric modulated arc therapy, to a total dose of 45 Gy in 25 fractions over 5 weeks. MRI performed 2 months later revealed complete response and she is disease free for the past 5 months.

Primary leiomyosarcoma of the spine: A case report and literature review

RATIONALE

Primary leiomyosarcoma of the bone was firstly reported by Evans and Sanerkin in 1965, whereas primary leiomyosarcoma of the vertebra is extremely rare. Because of the rarity of primary vertebral leiomyosarcoma, the diagnosis, treatment, and clinical outcome still remain controversial. Here we report a special case of primary leiomyosarcoma in the thoracic vertebra.

PATIENT CONCERNS

A 47-year-old female patient was admitted to our institution with the chief complaint of persistent back pain for 4 weeks. She had no symptoms of numbness, weakness, pain, and abnormal sensation in her extremities.

DIAGNOSES

Neurological examination on admission revealed no obvious abnormality. Magnetic resonance imaging showed a bone destruction of the T11 vertebral body and the right pedicle. Therefore, primary vertebral leiomyosarcoma was suspected. Pathological hematoxylin and eosin staining of the resected tumor revealed a diagnosis of polymorphic undifferentiated sarcoma. Furthermore, to identify the subtype of this sarcoma, the immunohistochemical staining of the tumor was performed with each of the various antibodies and the results are epithelial membrane antigen (-), H-caldesmon (-), desmin (+), smooth muscle actin (+), S-100 (-), myogenin (-), pan-keratin (-), and Ki-67 (positive rate: 20%). Finally, the patient was diagnosed as primary vertebral leiomyosarcoma.

INTERVENTIONS

the anterior corpectomy and autogenous iliac bone graft with instrumentation combined with the posterior spinal canal decompression and fusion with the pedicle screw system were performed through an anterior-posterior union approach.

OUTCOMES

Neither clinical symptoms nor signs of tumor recurrence were detected within the follow-up of 6 months. In addition, 11 cases of the primary vertebral leiomyosarcoma reported in the literature were reviewed and summarized.

LESSONS

Exclusion of metastatic leiomyosarcoma by various imaging modalities and histopathological examinations, especially the immunohistochemical staining with various antibodies against the epithelial and mesenchymal cell markers, are critical for establishing the correct diagnosis of the primary vertebral leiomyosarcoma. Surgical resection, especially the total en bloc spondylectomy, is the main treatment option with a good outcome, albeit with a limited follow-up duration.

Primary multiple osseous leiomyosarcomas of the spine metastasizing to the skull

Primary osseous leiomyosarcoma of the spine is a very unusual condition, with only few cases being reported in the literature. In fact, this type of tumors arises from the smooth muscle cells and occurs usually in the uterus and the gastrointestinal tracts. If the spine should be involved, it occurs generally as a metastatic location. Location to the spine as a primary site is exceedingly rare. We present the case of a 37 years old female patient, with multiple spine levels involvement - to vertebral body and to posterior aspects of Vertebra, causing spinal cord compression syndrome. A secondary location to the skull was diagnosed one month later. Through a literature review, we analyze various aspects in the diagnosis and management of this rare entity.

Primary Intraosseous Smooth Muscle Tumor of Uncertain Malignant Potential: Original Report and Molecular Characterization

We report the first case of primary intraosseous smooth muscle tumor of uncertain malignant potential (STUMP) which is analogous to borderline malignant uterine smooth muscle tumors so designated. The tumor presented in the femur of an otherwise healthy 30-year-old woman. Over a 3-year period, the patient underwent 11 biopsies or resections and 2 cytologic procedures. Multiple pathologists reviewed the histologic material including musculoskeletal pathologists but could not reach a definitive diagnosis. However, metastases eventually developed and were rapidly progressive and responsive to gemcitabine and docetaxel. Molecular characterization and ultrastructural analysis was consistent with smooth muscle origin, and amplification of unmutated chromosome 12p and 12q segments appears to be the major genomic driver of this tumor. Primary intraosseous STUMP is thought to be genetically related to leiomyosarcoma of bone, but likely representing an earlier stage of carcinogenesis. Wide excision and aggressive follow-up is warranted for this potentially life-threatening neoplasm.

Intraosseous Leiomyoma of the Tibia. A Case Report

Introduction:

Leiomyoma is benign smooth-muscle tumor most commonly arising in the uterus, the gastrointestinal tract, and the skin. Leiomyomata are infrequently seen in the extremities and rarely seen in the bone. It is usually presented by a gradually increasing pain with nonspecific radiological findings, and could be a differential diagnosis for wide range of bone tumors.

Case presentation:

We report a case of a 73-year-old Japanese female patient with a painful intraosseous leiomyoma involving the proximal tibia. The patient had undergone tumor excision with wide margin, immediate weight bearing was allowed, pain had been relieved and the patient was satisfied with no recurrence, malignant change, distant metastases or functional impairment. We reviewed all published cases of intraosseous leiomyomata in English literature.

Conclusion:

Diagnosis of Intraosseous leiomyoma of the extremities is difficult due to extreme rarity of the tumor and absence of pathognomonic radiological sign in X-ray, CAT, or even MRI. While the exact diagnosis is only achieved by histopathological examination and with immunohistochemistry stains, which can differentiate it from malignancy, especially from the much less rare leiomyosarcoma. Orthopedic oncologists have to include this rare benign tumor in the differential diagnosis of any intraosseous lesion with gradually worsening and long-standing pain, despite of benign imaging characters. Different histological patterns of leiomyoma do exist, however there is no difference in prognosis or treatment options. Treatment standard includes wide excision with autologous bone graft whenever possible. Internal fixation may be necessary if the bone defect is large or there is thinning out of the cortex that may lead to pathological fracture.

Primary leiomyosarcoma of femur

Primary leiomyosarcoma of the bone is exceedingly rare. In this case, we describe a middle-aged female with a primary leiomyosarcoma of the distal femur. The patient was treated by hip disarticulation. The patient continues to be disease-free at one-year follow-up.

Diagnosis, prognosis, and management of leiomyosarcoma: recognition of anatomic variants

PURPOSE OF REVIEW

The purpose of this review is to present the most recent advances in the diagnosis of the more common leiomyosarcoma (LMS) anatomic variants, potentially useful prognostic markers that have recently been identified and the systemic approaches currently used or under evaluation to improve the outcome of patients with this disease.

RECENT FINDINGS

Over the last few years emphasis has been placed on incorporating effective imaging tools and using pathological biomarkers in the diagnostic workup of LMS. Moreover, efforts are being made to identify meaningful prognostic and predictive parameters that will aid the development of effective novel therapeutics. The number of systemic therapies available to treat LMS has increased over the last decade, but the selection of systemic therapy is not based on the anatomic origin of LMS.

SUMMARY

Currently, the only curative option in LMS is surgery and despite progress in systemic therapy the outcome of patients with advanced/metastatic disease remains poor. Better understanding of the underlying biology of the LMS variants, improved diagnostics and more effective, less toxic therapeutic agents are required.

Intraosseous leiomyosarcoma arising in the epiphysis of the distal femur

Herein, we present a rare case of intraosseous leiomyosarcoma arising in the epiphysis of the distal femur and showing unusual radiographic features. A 44-year-old man presented with a pain in the left knee joint. Computed tomography revealed an intraosseous lesion with slightly increased attenuation and a thin marginal sclerotic rim in the femoral medial condyle. The signal of the lesion was hypointense on T1-weighted magnetic resonance (MR) images and hyperintense on fat-suppressed T2-weighted MR images. After gadolinium administration, the signal of the lesion was moderately and diffusely enhanced. The histological diagnosis of leiomyosarcoma was made based on a preoperative core biopsy specimen. Microscopic examination of the resected specimen revealed an ill-defined intraosseous tumor composed of proliferated atypical and mildly pleomorphic smooth muscle cells permeating among the bone trabeculae with only focal destruction of the bone trabeculae and low mitotic activity, indicating low grade leiomyosarcoma. The bone trabeculae at the periphery of the tumor were mildly thickened and anastomosed with a rim of an increased number of osteoblasts. Systemic examination showed no tumorous lesions in other anatomical sites. Leiomyosarcomas rarely present in the bone as a diffuse intertrabecular growth, even in low grade tumors.

Metastatic leiomyosarcoma presenting as bilateral, multifocal breast masses

Here we describe a case of metastatic leiomyosarcoma presenting as bilateral, multifocal breast masses. This case represents the convergence of three rare entities: leiomyosarcoma of unknown primary origin, metastases to the breast and bilateral, multicentric breast disease.

Myogenic tumors in children and adolescents

Neoplasms of striated and smooth muscle in children are a diverse group of neoplasms that have some unique aspects in contrast to these tumors in adults. Rhabdomyosarcoma is the most common soft tissue sarcoma of infancy and childhood and is relatively common in adolescents. In contrast, smooth muscle tumors are relatively rare, and the various types of rhabdomyoma and smooth and skeletal muscle hamartomas are very uncommon. In recent years, the understanding of the pathologic and genetic aspects of rhabdomyosarcoma has been enhanced by adjunct techniques, such as immunohistochemistry and cytogenetic or molecular genetic analysis. The current classification of rhabdomyosarcoma emphasizes the histologic-prognostic correlations. This article reviews the clinicopathologic features of striated and smooth muscle tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents and the differential diagnosis.

Primary leiomyosarcoma of bone: analysis of prognosis

Leiomyosarcoma of bone is just one of the variants of spindle cell sarcoma of bone characterised by the expression of desmin and other markers indicating a significant element of smooth muscle in the tumour, without osteoid production we have investigated the management and outcome of this rare type of primary malignant bone tumour. Method. Retrospective review of data stored on a prospective database. Results. In a database of 3364 patients with primary malignant bone sarcomas, 31 patients were identified with a primary leiomyosarcoma of bone. There were 12 males and 19 females with a mean age of 46 and tumour size of 8 cm. The most common site was the distal femur followed by the proximal tibia. Treatment was with chemotherapy and surgical resection. Seven of the patients had metastases at diagnosis. Surgery was carried out in 28 patients, 8 having amputation and 20 limb salvage. Three patients developed local recurrence, but half developed metastases. All patient disease-specific survival was 57% at five years and 44% at 10 yrs but for those without metastases was 82% and 60%, respectively. The only prognostic factors were metastases at diagnosis. Conclusion. Leiomyosarcoma of bone is a very rare primary malignant bone tumour affecting a predominantly older population. Despite the high incidence of metastases, survival is better than for other bone sarcomas for those without metastases at diagnosis.

Skeletal Metastasis

The most commonly diagnosed tumor in the skeleton represents metastatic disease. Metastatic carcinoma should be the first consideration in older patients with atypical radiologic findings or clinical features suggestive of a bone lesion. The primary goal in the setting of skeletal metastasis is usually palliation.

Leiomyosarcoma of bone: a case report

The aim of this paper is to present clinicopathologic features and immunohistochemical findings of a primary leiomyosarcoma of bone occurring in the proximal femur of a 46-year-old Caucasian male patient. Each case report on this exceedingly rare entity contributes to the notion of this disease.

Partial spondylectomy for primary leiomyosarcoma of C2 vertebra

STUDY DESIGN

A primary leiomyosarcoma located on the left side of the C2 is reported. Left-sided partial spondylectomy and anterior reconstruction with posterior stabilization was performed by a two-staged operation.

OBJECTIVE

To emphasize the occurrence of primary leiomyosarcoma and the importance of proper stabilization in the upper cervical spine.

SUMMARY OF BACKGROUND DATA

Leiomyosarcoma is a rare malignant neoplasm of the bone and the primary leiomyosarcoma of the spine is extremely rare. Radical tumor excision is the goal in case of vertebral leiomyosarcoma, but to both gain surgical access to the upper cervical spine and obtain anterior reconstruction is challenging.

METHODS

Leiomyosarcoma of the C2 in a 25-year-old woman with mild neurologic deficits is reported. A left-sided partial spondylectomy of C2 was performed. The defect of the vertebral body was reconstructed by expandable titanium prosthesis, and posterior craniocervical fixation was performed by the polyaxial screws in the lateral masses and rod/plates.

RESULTS

The surgical margin was very small. The pathology of the tumor was reported as leiomyosarcoma. No sign of local recurrence or metastasis was evident 1 year after surgery.

CONCLUSION

Leiomyosarcoma, although rare, should be kept in mind as one of the possible diagnoses when a patient with an upper cervical tumor is presented and complete tumor removal must be the goal.

Primary leiomyosarcoma of bone--a clinicopathologic study of 8 uncommon cases with immunohistochemical analysis and clinical outcomes

Primary leiomyosarcoma of bone is a rare and a diagnostically challenging tumor entity. Over a 7-year period, we identified 8 such cases that fulfilled the diagnostic criteria in 6 men and 2 women, with age ranging from 25 to 59 years (mean, 42.7 years). All cases were noted in the lower limbs, including femur and tibia as the commonly involved bones in 4 and 3 cases, respectively. On radiography, the most consistent feature was a solitary osteolytic lesion with cortical destruction, unassociated with matrix formation. On histopathology, all cases showed spindly sarcomatous cells, mostly arranged in fascicles and whorls. Of 8 cases, 6 (75%) were of high grade. Prominent vasculature was noted in 5 cases. Two cases displayed focal mineralization, including calcification and heterotropic woven bone formation in 1 case each, but lacked malignant osteoid or chondroid matrix. One case showed osteoclast-like giant cells. On immunohistochemistry, smooth muscle actin was diffusely positive in all cases (100%), desmin was positive in 6 (75%) of 8 cases, and h-caldesmon was positive in 5 (83.3%) of 6 cases. Five cases underwent surgery, including 3 amputations and 2 wide excisions. One case underwent chemotherapy. On follow-up, 5 cases developed metastasis, including 1 case with another, who died within 17 and 5 months. Leiomyosarcoma of bone is uncommon and diagnostically challenging. An index of suspicion is necessary for this diagnosis, especially in cases of lytic, destructive bone lesions, unassociated with matrix production, that show spindly sarcomatous cells on histopathology. Immunohistochemical analysis, including an optimum panel formed by smooth muscle actin (diffuse positivity), desmin, and h-caldesmon, is necessary for substantiating this diagnosis. Surgery forms the treatment mainstay. The prognosis appears to be dismal.

Collagenous myofibroblastic tumor of the mandible: case report of a unique locally aggressive neoplasm

We report a locally aggressive collagenous myofibroblastic neoplasm of the mandible in an 18-year-old male. Clinically, the lesion presented with rapid growth and irregular mandibular bone destruction. Grossly, the tumor was 10 cm in greatest dimension, light-tan, firm, and involving the posterior one-thirds of the body and inferior half of the left mandibular ramus. Histologically, the lesion was composed of a loose spindle cell proliferation interspersed with periodic dense bands of collagen. The spindle cells reacted positively to smooth muscle actin, calponin, and focally to desmin and were negative for S-100, pan-cytokeratin, CD99, CD34 and caldesmon, supporting myofibroblastic derivation. At our 4 year follow-up, the patient remained free of local recurrence and surgery related complications. The clinicopathologic findings and the differential diagnosis of this lesion is presented and discussed.