Pleomorphic leiomyosarcoma of the soft parts: a reassessment by histology and immunohistochemistry of pleomorphic soft tissue sarcomas

Histologically it is often difficult to differentiate malignant fibrous histiocytoma (MFH) from leiomyosarcoma. Sixty-three cases formerly diagnosed as pleomorphic soft tissue sarcomas were examined by immunohistochemistry. We identified three different types according to its positivity for the myogenic markers: A) positive cells with a fascicular pattern, 13 cases (26%); B) a small number of scattered positive cells, 29 cases (57%); C) negative for markers, 9 cases (17%). We reassessed 51 MFHs as follows: A type as pleomorphic leiomyosarcoma, B+C types as MFH. Pleomorphic leiomyosarcomas were also positive for collagen type IV around the compactly arranged individual tumor cells. An imunohistochemical analysis and detection of fascicular structures are thus considered to be necessary in order to distinguish between leiomyosarcoma and MFH.     

Genetic aberrations in soft tissue leiomyosarcoma

Leiomyosarcoma is a malignant mesenchymal tumor composed of cells showing smooth muscle differentiation. This tumor usually occurs in middle-aged or older adults, and forms a significant percentage of retroperitoneal, vascular, extremity, and uterine sarcomas. Leiomyosarcomas are most often associated with complex karyotypes with numerous chromosomal gains and losses. Some of these cytogenetic and molecular genetic aberrations correlate with histopathologic features and clinical outcomes. Identification of genetic alterations with specific identification of oncogenes and tumor suppressor genes may lead to additional insights into the tumorigenesis of leiomyosarcoma and the opportunity to confer the benefits of targeted therapy.     

Epigenetic signatures differentiate uterine and soft tissue leiomyosarcoma

Leiomyosarcomas (LMS) are diverse, rare, and aggressive mesenchymal soft tissue sarcomas. Epigenetic alterations influence multiple aspects of cancer, however epigenetic profiling of LMS has been limited. The goal of this study was to delineate the molecular landscape of LMS for subtype-specific differences (uterine LMS (ULMS) vs soft tissue LMS (STLMS)) based on integrated analysis of DNA methylation and gene expression to identify potential targets for therapeutic intervention and diagnosis. We identified differentially methylated and differentially expressed genes associated with ULMS and STLMS using DNA methylation and RNA-seq data from primary tumors. Two main clusters were identified through unsupervised hierarchical clustering: ULMS-enriched cluster and STLMS-enriched cluster. The integrated analysis demonstrated 34 genes associated with hypermethylation of the promoter CpG islands and downregulation of gene expression in ULMS or STLMS. In summary, these results indicate that differential DNA methylation and gene expression patterns are associated with ULMS and STLMS. Further studies are needed to delineate the contribution of epigenetic regulation to LMS subtype-specific gene expression and determine the roles of the differentially methylated and differentially expressed genes as potential therapeutic targets or biomarkers.     

四肢软组织平滑肌肉瘤的治疗与预后探讨

目的探讨四肢软组织平滑肌肉瘤(leiomyosarcoma,LMS)的临床特征、治疗方法及预后。方法回顾分析南京医科大学第一附属医院2008年1月至2015年4月收治的15例四肢软组织平滑肌肉瘤患者的临床资料,并复习相关文献。结果病变位于上肢1例,下肢14例。影像学表现缺乏特异性,CT和MRI有助于确定病变范围和手术方案。AJCC分期ⅠA期2例,ⅠB期1例,ⅡA期3例,ⅡB期6例,Ⅲ期1例,Ⅳ期2例。2例行髋关节离断术,其余13例行保肢术,其中6例辅以化疗,2例辅以放疗。15例患者均获随访12.0~215.0个月,中值时间42个月,其中9例发生复发和(或)转移;5例死于肺转移,10例存活患者中3例为带瘤生存。结论手术为四肢软组织平滑肌肉瘤的主要治疗手段,规范放化疗有助于提高患者生存率。发生远处转移的患者预后欠佳。     

前后侧联合入路切除大腿巨大软组织肉瘤

目的介绍经前后侧联合入路并结扎股深动脉切除大腿巨大软组织肉瘤的经验。方法对初发或复发的8例大腿巨大软组织肉瘤术前常规行MRI和DSA检查，采用经前后侧联合入路并结扎股深动脉行肿瘤广泛切除术，其中1例行术前化疗及术后放疗，3例行术后放疗，3例术后局部复发再次行广泛切除术后放疗，1例术前术后均无辅助治疗。结果8例中2例术后出现切口边缘皮肤坏死，1例经换药治愈，1例行局部推移皮瓣术后治愈。8例术后随访2～6年，4例无瘤正常生存，3例1～2年内局部复发再次行广泛切除术，术后无瘤正常生存，1例无任何辅助治疗者术后多次局部复发行姑息性局部切除术，6年后因全身衰竭死亡。结论对初发或复发的大腿巨大软组织肉瘤术前常规行MRI和DSA检查评估其局部切除的可行性，采用经前后侧联合入路并结扎股深动脉行肿瘤广泛切除术，术后辅助放疗，是较好的保肢治疗方法。术后局部复发是较常见的并发症，再次行复发灶广泛切除术及术后放疗仍可取得较好的疗效。     

The Application of Spectral Karyotyping in Leukemia

Spectral karyotyping (SKY) is a novel cytogenetic technique, which has been developed to unambiguously display and identify all 24 human chromosomes at one time without previous knowledge of any abnormalities involved. SKY can discern aberrations that fail to be easily detected by conventional banding techniques and by fluorescent in situ hybridization (FISH). Therefore SKY is highly accurate, highly sensitive, and highly prognostic. In this report the featurese and application of SKY in studies of leukemia are reviewed.     

Genomic profiling of bone and soft tissue tumors with supernumerary ring chromosomes using tiling resolution bacterial artificial chromosome microarrays

Ring chromosomes and/or giant marker chromosomes have been observed in a variety of human tumor types, but they are particularly common in a subgroup of mesenchymal tumors of low-grade or borderline malignancy. These rings and markers have been shown to contain amplified material predominantly from 12q13-15, but also sequences from other chromosomes. Such amplified sequences were mapped in detail by genome-wide array comparative genomic hybridization in ring-containing tumor samples from soft tissue (n = 15) and bone (n = 6), using tiling resolution microarrays, encompassing 32 433 bacterial artificial chromosome clones. The DNA copy number profiles revealed multiple amplification targets, in many cases highly discontinuous, leading to delineation of large numbers of very small amplicons. A total number of 356 (median size: 0.64 Mb) amplicons were seen in the soft tissue tumors and 90 (median size: 1.19 Mb) in the bone tumors. Notably, more than 40% of all amplicons in both soft tissue and bone tumors were mapped to chromosome 12, and at least one of the previously reported recurrent amplifications in 12q13.3-14.1 and 12q15.1, including SAS and CDK4, and MDM2, respectively, were present in 85% of the soft tissue tumors and in all of the bone tumors. Although chromosome 12 was the only chromosome displaying recurrent amplification in the bone tumors, the soft tissue tumors frequently showed recurrent amplicons mapping to other chromosomes, that is, 1p32, 1q23-24, 3p11-12, 6q24-25 and 20q11-12. Of particular interest, amplicons containing genes involved in the c-jun NH2-terminal kinase/mitogen-activated protein kinase pathway, that is, JUN in 1p32 and MAP3K7IP2 (TAB2) in 6q24-25, were found to be independently amplified in eight of 11 cases with 12q amplification, providing strong support for the notion that aberrant expression of this pathway is an important step in the dedifferentiation of liposarcomas.     

AP2 protein expression as a diagnostic marker in soft tissue tumours

Purpose/Methods: The aP2 gene product (aP2 protein) is known to be expressed by preadipocytes and other immature fat cells in vitro. A mouse monoclonal antibody raised against an 18 amino acid segment of the aP2 protein was found to react with lipoblasts and fetal fat cells in paraffin sections of soft tissue tumours of adipose differentiation. In this immunohistochemical study, we have further examined the diagnostic utility of aP2 expression in distinguishing tumours of adipose differentiation from other benign and malignant soft tissue tumours.Result and discussion aP2 was strongly expressed by lipoblasts in lipoblastomas and all types of liposarcoma as well as brown fat cells in hibernomas. Optimal conditions for immunohistochemical identification of lipoblasts in tumours of adipose differentiation was noted when the antibody was diluted 1:30 to 1:50. Small lipoblast-like fat cells in pleomorphic lipoma and spindle cell lipoma also showed variable staining for aP2 at this dilution of the antibody. Most benign and malignant soft tissue tumours were distinguished by their absence of staining for aP2 protein, but some cases of myxoma, malignant fibrous histiocytoma, synovial sarcoma and leiomyosarcoma contained tumour cells which reacted for aP2. aP2 protein expression is likely to prove a useful means of distinguishing lipoblasts in liposarcoma but it should be used as part of a tumour panel to exclude expression in other forms of mesenchymal tumour.     

Prognostic factors in soft tissue leiomyosarcoma of the extremities: a retrospective analysis of 42 cases.

AIMS: Soft tissue leiomyosarcomas (LMS) are rare tumours which are associated with a poor prognosis. The goals of the present study were to describe the clinico-pathological and prognostic features of 42 patients affected by soft tissue LMS of the extremities. METHODS: The following clinical and pathological parameters were analysed: age, sex, site, size, depth, previous surgical procedures, stage, histological type, nuclear atypia, grade, mitotic activity, necrosis, surgical margins, therapy. Disease-free survival rates were calculated. RESULTS: The overall 2-year and 5-year disease free survival rates were 42.3% and 32.6%, respectively. By univariate analysis, tumour size (< or =10 cm vs. >10 cm; p = 0.01), average mitotic rate (< or =19/10 HPF vs. >19/10 HPF; p = 0.05), type of excision (wide vs. marginal or intralesional; p = 0.001) and adjuvant radiotherapy (none vs. brachytherapy+external beam radiotherapy vs. external beam radiotherapy; p = 0.02) were significantly correlated with disease progression. By multivariate analysis, the only factor that was found to be an independent predictor of disease relapse was type of excision (p = 0.001). CONCLUSIONS: Large tumour size and high mitotic rate resulted adverse prognostic factors. Adjuvant radiation therapy, in combination with wide surgical excision, allowed the best chance of cure.     

Incidental computed tomography diagnosis of a giant oesophageal leiomyosarcoma

Leiomyosarcoma of the oesophagus is a very unusual tumour; only 53 cases have been reported in the English-language literature. A case is reported here of a patient with a giant leiomyosarcoma, without any symptoms of dysphagia. The diagnosis was made incidentally during CT examination of the chest for detection of possible pulmonary metastases from a coexisting carcinoma of the bladder. This was confirmed by a barium swallow, oesophagoscopy and tissue diagnosis. The literature pertaining to this most uncommon tumour is reviewed.     

Non-random chromosomal rearrangements in pancreatic cancer cell lines identified by spectral karyotyping

The molecular events involved in pancreatic cancer are becoming increasingly well characterized, with mutations in the dominant oncogene KRAS and the tumour suppressor genes TP53, CDKN2A and MADH4 being typically observed. However, other genetic abnormalities remain to be identified and molecular cytogenetics may be useful to detect chromosomal loci involved in recurrent rearrangements. We have used spectral karyotyping to characterize cytogenetic aberrations in a panel of 20 human pancreatic carcinoma cell lines and confirmed their identities by dual and triple color fluorescence in situ hybridization. The most common partial or whole-arm gains involved 5p, 7q, 12p, 1q, 7p, 5q, 9p, 9q and 11p. The most common partial or whole-arm losses affected 9p, 11q, 18q, 3p, 2q and 1p, as well as the short arms of the acrocentric chromosomes. Spectral karyotyping allowed us to identify a number of recurrent structural aberrations, all of them unbalanced: most frequently i(5)(p10), del(11)(q23), i(12)(p10), i(1)(q10), del(7)(q22) and del(10)(p11). Spectral karyotyping mapped the complex aberrations occurring in pancreatic cancer cell lines and identified non-random patterns of chromosomal rearrangement. This comprehensive characterization should be useful to direct future investigation. The observation that loss at 11q and gains at 5p with i(5)(p10) and 12p with i(12)(p10) are more frequent changes than previously reported would justify more intensive investigation of these chromosomal regions.     

Immunohistochemistry of soft tissue tumors. Myoglobin as a tumor marker for rhabdomyosarcoma

Myoglobin, found exclusively in striated muscle, can be considered a fetal antigen. This study investigated its usefulness as a tumor marker for rhabdomyosarcoma (RMS) using an immunoperoxidase technique. Eight-nine percent (89%) or 27 rhabdomyosarcomas contained immunoreactive myoglobin. In contrast, all other soft tissue tumors (54), carcinomas (10), and numerous normal tissues including smooth muscle were negative. Among RMS, staining correlated directly with cytoplasmic differentiation regardless of histologic type. Importantly, six of nine small cell RMS with no initially appreciated cytoplasm were positive, although focally. Since the three negative RMS had only limited tissue available for study, it remains possible that all RMS would exhibit rare positivity if sizeable specimens were tested. Myoglobin should be considered an extremely sensitive and specific tissue tumor marker for rhabdomyosarcoma of considerable clinical importance.     

Carbonic anhydrase IX as a marker for poor prognosis in soft tissue sarcoma.

PURPOSE: Hypoxia is associated with malignant progression and poor outcome in several human tumors, including soft tissue sarcoma. Recent studies have suggested that carbonic anhydrase (CA) IX is an intrinsic marker of hypoxia, and that CA IX correlates with poor prognosis in several types of carcinoma. The aim of this study was to quantify the extent of CA IX expression and to investigate whether CA IX is a marker for poor prognosis in soft tissue sarcoma patients at high risk of developing metastasis. EXPERIMENTAL DESIGN: Archival paraffin-embedded blocks were retrieved from 47 patients with deep, large, high-grade soft tissue sarcoma. Sections from two separate and representative tumor areas were immunostained for CA IX, and the CA IX-positive area fraction was quantified by image analysis, excluding areas of normal stroma and necrosis that were identified from serial H&E-stained sections. Patients were then subject to survival analysis. RESULTS: CA IX-positive area fractions of viable tumor tissue varied significantly between tumors (range, 0-0.23; median, 0.004), with positive membranous CA IX staining in 66% (31 of 47) of the tumors. Patients with CA IX-positive tumors had a significantly lower disease-specific and overall survival than patients with CA IX-negative tumors (P = 0.033 and P = 0.044, respectively). CONCLUSIONS: These data suggest that CA IX, a potential intrinsic marker of hypoxia, predicts for poor prognosis in patients with deep, large, high-grade soft tissue sarcoma. Larger studies are required to determine whether CA IX has independent prognostic value in this group of tumors.     

Clinical course of nonvisceral soft tissue leiomyosarcoma in 225 patients from the Scandinavian Sarcoma Group

BACKGROUND: Leiomyosarcoma of nonvisceral soft tissues is an uncommon malignant tumor; thus, only small numbers of cases have been reported. This study was based on a large series of patients from the Scandinavian Sarcoma Group Register acquired during a 15-year period (from 1986 to 2001). Follow-up information was available for all patients. METHODS: The authors analyzed the clinical features of 225 patients with cutaneous, subcutaneous, or deep-seated leiomyosarcoma of the extremities, trunk wall, and superficial parts of the head and neck region to determine the natural course of the disease. Only patients who received their treatment at a specialist sarcoma center were included. Re-evaluation of histopathology was performed. RESULTS: The age of the patients (121 women and 104 men) ranged from 20 years to 98 years (median, 70 years), and the tumors ranged in size from 0.6 cm to 35 cm (median, 4.0 cm). Eighty-two percent of the tumors were classified as high grade. The median follow-up for survivors was 5.5 years. The local treatment was adequate in 154 of 206 patients (75%) who were without metastasis at presentation. At 10 years, 84% of the 206 patients with localized disease at presentation were free from local recurrence, 66% remained metastasis free, and 49% were alive. Multivariate analysis showed that higher malignancy grade (P = .006), larger tumor size (P = .003), and deeper tumor location (P = .002) were correlated significantly with decreased metastasis-free survival, inadequate local treatment was correlated with local recurrence (P = .007), and high malignancy grade was correlated with decreased overall survival (P = .007). CONCLUSIONS: The long-term prognosis for patients with subcutaneous and deep-seated soft tissue leiomyosarcoma remains poor despite the ability to achieve adequate local control through nonmutilating surgery with or without radiotherapy.     

Irradiation-induced marker chromosomes in a metastasizing murine tumor

We have used irradiation to induce marker chromosome formation in a metastasizing murine tumor with a stable karyotype. The induced recombinant chromosomes then served to determine whether metastases were of clonal or multicellular origin. Cumulative data were obtained from four series of experiments on spontaneous metastases originating from tumors grown from irradiated cells; 20 of these metastases expressed unique chromosomal alterations consistent with a clonal origin. The majority of metastasis-derived cell populations remain stable with respect to their marker chromosomes in culture as well as in successive animal transplantation. In several instances, however, chromosomal instability was sufficient to obscure the cellular origins of individual metastases. A few metastases showed mixed chromosomal patterns initially that were consistent with multicellular origin, but repeat examinations have revealed a chromosomal instability which persisted during propagation in culture. The frequency of chromosomal recombinants in metastases from the combined series was sufficient to suggest biological and statistical significance. The morphology of recombinants was not associated with radiation dose but appeared as an apparently random response of the tumor population in different experiments. Analysis of chromosomal markers by banding techniques was performed to determine if specific chromosomes or chromosomal sites were associated with tumor cells from metastatic foci (a host-selected subpopulation with a metastatic phenotype). Our results did not reveal preferential involvement of whole chromosomes or intrachromosomal sites in recombinant formation.