Molecular cytogenetic analysis of uterine leiomyoma and leiomyosarcoma by comparative genomic hybridization

Benign Metastasizing Leiomyoma: Is "Wait and Watch" Strategy Feasible?

Benign metastasizing leiomyoma (BML) is a rare disease that affects women with a history of uterine leiomyoma. The aim of this study is to investigate the clinical characteristics and outcome patterns. We collected 385 cases from previous reports indexed in PubMed and Google Scholar and made a thorough review. All relevant clinical parameters were carefully reviewed, including age at diagnosis, clinical presentations, course of disease, medical history, imaging, molecular tests, treatment, and outcomes. Univariate survival analysis was performed to investigate the effects of treatment strategies on outcomes. The mean age at diagnosis was 46.2 years. The most common site for the metastasis was lung, and followed by abdomen/pelvis/retroperitoneum, bone, lymph nodes, and heart. The medical histories and molecular alterations were non-specific, and the pathogenesis was still unclear. Due to its unresectable nature, hormone deprivation treatment, including oophorectomy and hormone drugs, is the most effective strategy to reduce or delay tumor progression. The present study may provide a useful consultation for diagnosing and managing BMLs.

Clinicopathologic and Molecular Characteristics of Epstein-Barr Virus-Associated Smooth Muscle Tumor Compared With Those of Leiomyoma and Leiomyosarcoma

Epstein-Barr virus (EBV)-associated smooth muscle tumors (EBV-SMTs) are rare smooth muscle neoplasms exclusively associated with immunosuppression, such as in patients with HIV/AIDS, posttransplant, and congenital immunodeficiency. However, the genomic landscape of EBV-SMTs is poorly understood. Leiomyosarcomas harbor genomic instability and multiple recurrent DNA copy number alterations, whereas leiomyomas lack such changes. Thus, this study aimed to fill this knowledge gap by characterizing copy number alterations in EBV-SMTs and correlating this information with clinicopathologic characteristics. Our study investigated and compared the pathologic characteristics and copy number profiles of 9 EBV-SMTs (from 7 post-transplant and AIDS patients), 6 leiomyomas, and 7 leiomyosarcomas, using chromosomal microarray platforms. Our results showed a lower copy number alteration burden in EBV-SMTs and leiomyoma than in leiomyosarcoma. This contrast in the molecular profile between EBV-SMTs and leiomyosarcoma is concordant with the different clinical behaviors and pathologic characteristics exhibited by these tumors. Despite having an overall copy number alteration profile closer to leiomyoma, recurrent copy number gain of oncogenes, such as RUNX1, CCND2, and ETS2, was found in EBV-SMTs. Epigenetic alterations may play an important role in tumorigenesis as recurrent copy number gains were found in histone deacetylases. A gene enrichment analysis also demonstrated enrichment of genes involved in the host response to viral infection, suggesting that the tumor immune microenvironment may play an important role in EBV-SMT tumorigenesis.

A View on Uterine Leiomyoma Genesis through the Prism of Genetic, Epigenetic and Cellular Heterogeneity

Uterine leiomyomas (ULs), frequent benign tumours of the female reproductive tract, are associated with a range of symptoms and significant morbidity. Despite extensive research, there is no consensus on essential points of UL initiation and development. The main reason for this is a pronounced inter- and intratumoral heterogeneity resulting from diverse and complicated mechanisms underlying UL pathobiology. In this review, we comprehensively analyse risk and protective factors for UL development, UL cellular composition, hormonal and paracrine signalling, epigenetic regulation and genetic abnormalities. We conclude the need to carefully update the concept of UL genesis in light of the current data. Staying within the framework of the existing hypotheses, we introduce a possible timeline for UL development and the associated key events—from potential prerequisites to the beginning of UL formation and the onset of driver and passenger changes.

A novel uterine leiomyoma subtype exhibits NRF2 activation and mutations in genes associated with neddylation of the Cullin 3-RING E3 ligase

Uterine leiomyomas, or fibroids, are the most common tumors in women of reproductive age. Uterine leiomyomas can be classified into at least three main molecular subtypes according to mutations affecting MED12, HMGA2, or FH. FH-deficient leiomyomas are characterized by activation of the NRF2 pathway, including upregulation of the NRF2 target gene AKR1B10. Here, we have identified a novel leiomyoma subtype showing AKR1B10 expression but no alterations in FH or other known driver genes. Whole-exome and whole-genome sequencing revealed biallelic mutations in key genes involved in neddylation of the Cullin 3-RING E3 ligase, including UBE2M, NEDD8, CUL3, and NAE1. 3′RNA sequencing confirmed a distinct molecular subtype with activation of the NRF2 pathway. Most tumors displayed cellular histopathology, perivascular hypercellularity, and characteristics typically seen in FH-deficient leiomyomas. These results suggest a novel leiomyoma subtype that is characterized by distinct morphological features, genetic alterations disrupting neddylation of the Cullin 3-RING E3 ligase, and oncogenic NRF2 activation. They also present defective neddylation as a novel mechanism leading to aberrant NRF2 signaling. Molecular characterization of uterine leiomyomas provides novel opportunities for targeted treatment options.

Cytogenomic Profile of Uterine Leiomyoma: In Vivo vs. In Vitro Comparison

We performed a comparative cytogenomic analysis of cultured and uncultured uterine leiomyoma (UL) samples. The experimental approach included karyotyping, aCGH, verification of the detected chromosomal abnormalities by metaphase and interphase FISH, MED12 mutation analysis and telomere measurement by Q-FISH. An abnormal karyotype was detected in 12 out of 32 cultured UL samples. In five karyotypically abnormal ULs, MED12 mutations were found. The chromosomal abnormalities in ULs were present mostly by complex rearrangements, including chromothripsis. In both karyotypically normal and abnormal ULs, telomeres were ~40% shorter than in the corresponding myometrium, being possibly prerequisite to chromosomal rearrangements. The uncultured samples of six karyotypically abnormal ULs were checked for the detected chromosomal abnormalities through interphase FISH with individually designed DNA probe sets. All chromosomal abnormalities detected in cultured ULs were found in corresponding uncultured samples. In all tumors, clonal spectra were present by the karyotypically abnormal cell clone/clones which coexisted with karyotypically normal ones, suggesting that chromosomal abnormalities acted as drivers, rather than triggers, of the neoplastic process. In vitro propagation did not cause any changes in the spectrum of the cell clones, but altered their ratio compared to uncultured sample. The alterations were unique for every UL. Compared to its uncultured counterpart, the frequency of chromosomally abnormal cells in the cultured sample was higher in some ULs and lower in others. To summarize, ULs are characterized by both inter- and intratumor genetic heterogeneity. Regardless of its MED12 status, a tumor may be comprised of clones with and without chromosomal abnormalities. In contrast to the clonal spectrum, which is unique and constant for each UL, the clonal frequency demonstrates up or down shifts under in vitro conditions, most probably determined by the unequal ability of cells with different genetic aberrations to exist outside the body.

Investigation on factors related to uterine fibroids in rural women of northern Anhui province

AIM

Given the increasing prevalence of hysteromyoma among the Chinese rural women of childbearing age, it is imperative that more attention should be given to researching risk factors that predispose women to this condition so that early preventive measures may be taken. Our study investigates potential risk factors for uterine fibroids such as participants' demographic characteristics (age, ethnicity, education), physiological characteristics (age at menarche, primiparous age), and the occurrence of several different female reproductive diseases (vaginitis, pelvic inflammatory disease).

METHODS

2200 rural women of reproductive age were screened from a cross-sectional study carried out in the northern Anhui province. Data were collected by questionnaire surveys, gynecological and laboratory examinations and were subjected to univariate and multivariate analysis to evaluate the risk factors for uterine fibroids.

RESULTS

Of the 2200 women, 440 had uterine fibroids. In general, women with endometriosis, ovarian cysts and early menarche were more likely to suffer from hysteromyoma. Factors including higher parity, late age of first childbirth, and a regular menstrual cycle were associated with the reduced risk of uterine fibroids.

CONCLUSIONS

Our findings indicate that parameters such as earlier age of menarche, early primiparous age, lower parity and a variety of female reproductive diseases were associated with an increased risk of uterine fibroids. These findings may be used to guide the formulation of effective prevention and intervention protocols to improve the reproductive health of rural women.

Integrated histologic and molecular analysis of uterine leiomyosarcoma and 2 benign variants with nuclear atypia

Uterine leiomyosarcoma (LMS) is a rare but deadly disease. Due to poor understanding of the molecular and genetic causes of the disease, the diagnosis of LMS has been based primarily on histology. Nuclear atypia is one of hallmarks in LMS, however, it also occurs in 2 clinically benign variants, including smooth muscle tumors with fumarate hydratase alteration (SMT‐FH) and leiomyoma with bizarre nuclei (LM‐BN). In addition to nuclear atypia, many well recognized biomarkers used for LMS are also frequently overexpressed in LM‐BN, and the histogenesis and molecular natures for LM‐BN and LMS remain largely unknown. To characterize the molecular profiling of LMS, SMT‐FH, and LM‐BN, we performed integrated comprehensive genomic profiling including whole‐genome sequencing (WGS) and RNA sequencing and genomic microarray analyses to assess genome‐wide copy number alterations (CNAs) and immunohistochemistry (IHC) in all 3 tumor types. We found that both LM‐BN and LMS showed genomic instability and harbored extensive CNAs throughout the whole genome. By contrast, the SMT‐FH presented its characteristic 1q43‐44 deletions in all cases tested, with minimal CNAs in the rest of genomic regions. Further analyses revealed that LMS and LM‐BN groups showed similar patterns of CNAs that are tended to cluster together and separated from the SMT‐FH group. The integrated molecular profiling enabled the detection of novel and traditional biomarkers and showed excellent discrimination between LM‐BN and LMS. Our study suggests that LM‐BN, despite having similar nuclear atypia to SMT‐FH, showed similar genomic instability but distinct genomic alterations with its malignant counterpart of LMS. The integrated molecular profiling is of clinical importance in characterizing these rare uterine smooth muscle tumors.

Molecular Pathology: Predictive, Prognostic, and Diagnostic Markers in Uterine Tumors

This article focuses on the diagnostic, prognostic, and predictive molecular biomarkers in uterine malignancies, in the context of morphologic diagnoses. The histologic classification of endometrial carcinomas is reviewed first, followed by the description and molecular classification of endometrial epithelial malignancies in the context of histologic classification. Taken together, the molecular and histologic classifications help clinicians to approach troublesome areas encountered in clinical practice and evaluate the utility of molecular alterations in the diagnosis and subclassification of endometrial carcinomas. Putative prognostic markers are reviewed. The use of molecular alterations and surrogate immunohistochemistry as prognostic and predictive markers is also discussed.

Factors associated with uterine fibroid in Ghanaian women undergoing pelvic scans with suspected uterine fibroid

Background

Uterine fibroids are the most common benign tumours affecting premenopausal women and are often associated with considerable hospitalization and morbidity. Literature shows virtually no study concerning the quantification of the main factors associated with uterine fibroids in Ghanaian women. The purpose of this study was to assess the main factors associated with uterine fibroid among Ghanaian women presenting for ultrasound.

Method

A prospective cross-sectional study design was employed in this study. A total of two hundred and forty-four (244) women were consecutively evaluated from November 2011 to February 2012 using a 2–5 MHz curvilinear probe of Philips HD3 ultrasound machines at three centres in Accra using a trans-abdominal pelvic approach. Data was analysed with (SPSS) version 20.0 for windows, 2010; Chicago. The Pearson’s Chi-square test was used to determine associations between selected demographic and gynaecological characteristics and uterine fibroid appearance. All tests were two-tailed and p-value of less than 0.05 was interpreted as significant.

Results

The range, mean and standard deviation (SD) of the patients’ age were 14–54 years, 31.89 years and ± 7.92 respectively. Factors that associated significantly with uterine fibroid in Ghanaian women included obesity (X² = 17.3, p-value = 0.001), participant’s age range (X² = 47.4, p-value = 0.001), parity (X² = −10.169, p-value = 0.001), and age at last delivery (X² = 34.579, p-value = 0.001).

Conclusion

Uterine fibroid was mainly associated with women of older age group of the reproductive age than the younger age categories and also associated more with women with without children compared to those with more children. Moreover, it associated more with obese patients and patient with late age at last delivery.

Uterine fibroid characteristics and sonographic pattern among Ghanaian females undergoing pelvic ultrasound scan: a study at 3-major centres

BACKGROUND

Uterine fibroids are the most common benign tumours affecting premenopausal women and are often associated with considerable hospitalization and morbidity. The purpose of this study was to identify the uterine fibroid characteristics and sonographic patterns of uterine fibroids among Ghanaian women undergoing abdomino-pelvic or pelvic ultrasound scan at three major diagnostic centres. The outcome is expected to help in appropriate policy formulation in women care in Ghana.

METHOD

A total of two hundred and forty four (244) women were evaluated between November 2011-February 2012, using identical 2-5 MHz curvilinear probe of Philips HD3 ultrasound machines at three major diagnostic centers in Ghana, using a trans-abdominal pelvic approach.

RESULTS

The range, mean and standard deviation (SD) of the patients' ages were 14-54 years, 31.89 years and ± 7.92 respectively. The majority, 57.8% of the fibroids were intramural with only 4.4% noted as sub-mucosal. Most (55.6%) of the fibroids were located in more than one part of the uterus. The most popular (55.6%) echo pattern of the various fibroid nodules was mixed echogenicity.

CONCLUSION

The sonographic patterns of uterine fibroids among Ghanaian women have been assessed at three major diagnostic centres. The study shows that most Ghanaian women who have fibroids have degenerative fibroid nodules as these nodules demonstrate mixed echo patterns on ultrasound. The findings may aid in appropriate diagnosis and interventions in the country.

Epidemiological and genetic clues for molecular mechanisms involved in uterine leiomyoma development and growth

BACKGROUND

Uterine leiomyomas (fibroids) are highly prevalent benign smooth muscle tumors of the uterus. In the USA, the lifetime risk for women developing uterine leiomyomas is estimated as up to 75%. Except for hysterectomy, most therapies or treatments often provide only partial or temporary relief and are not successful in every patient. There is a clear racial disparity in the disease; African-American women are estimated to be three times more likely to develop uterine leiomyomas and generally develop more severe symptoms. There is also familial clustering between first-degree relatives and twins, and multiple inherited syndromes in which fibroid development occurs. Leiomyomas have been described as clonal and hormonally regulated, but despite the healthcare burden imposed by the disease, the etiology of uterine leiomyomas remains largely unknown. The mechanisms involved in their growth are also essentially unknown, which has contributed to the slow progress in development of effective treatment options.

METHODS

A comprehensive PubMed search for and critical assessment of articles related to the epidemiological, biological and genetic clues for uterine leiomyoma development was performed. The individual functions of some of the best candidate genes are explained to provide more insight into their biological function and to interconnect and organize genes and pathways in one overarching figure that represents the current state of knowledge about uterine leiomyoma development and growth.

RESULTS

In this review, the widely recognized roles of estrogen and progesterone in uterine leiomyoma pathobiology on the basis of clinical and experimental data are presented. This is followed by fundamental aspects and concepts including the possible cellular origin of uterine fibroids. The central themes in the subsequent parts are cytogenetic aberrations in leiomyomas and the racial/ethnic disparities in uterine fibroid biology. Then, the attributes of various in vitro and in vivo, human syndrome, rodent xenograft, naturally mutant, and genetically modified models used to study possible molecular mechanisms of leiomyoma development and growth are described. Particular emphasis is placed on known links to fibrosis, hypertrophy, and hyperplasia and genes that are potentially important in these processes.

CONCLUSIONS

Menstrual cycle-related injury and repair and coinciding hormonal cycling appears to affect myometrial stem cells that, at a certain stage of fibroid development, often obtain cytogenetic aberrations and mutations of Mediator complex subunit 12 (MED12). Mammalian target of rapamycin (mTOR), a master regulator of proliferation, is activated in many of these tumors, possibly by mechanisms that are similar to some human fibrosis syndromes and/or by mutation of upstream tumor suppressor genes. Animal models of the disease support some of these dysregulated pathways in fibroid etiology or pathogenesis, but none are definitive. All of this suggests that there are likely several key mechanisms involved in the disease that, in addition to increasing the complexity of uterine fibroid pathobiology, offer possible approaches for patient-specific therapies. A final model that incorporates many of these reported mechanisms is presented with a discussion of their implications for leiomyoma clinical practice.

A Novel Molecular Cytogenetic Finding of Leiomyomatosis Peritonealis Disseminata

BACKGROUND

Leiomyomatosis peritonealis disseminata (LPD) is a rare disease characterised by the subperitoneal proliferation of smooth muscle cells that form benign nodules. A few studies have aimed to reveal the pathogenesis of LPD without reaching a clear explanation.

METHODS

Karyotype analysis and array-comparative genomic hybridization (aCGH) of a human LPD case were performed to evaluate the role of chromosomal abnormalities in LPD pathogenesis.

RESULTS

The LPD nodules showed a 45, XX, del(7p), t(11; 17) (q23;q25),-22 de novo karyotype, and the aCGH analysis confirmed these deletions at 7p22.3-p12.1 (1,862,362-52,766,911 bp) and 22q11.23-q13.33 (21,973,915-49,265,116 bp) with lengths of 50.9 Mb and 27.3 Mb, respectively.

CONCLUSION

In this study, we described two large novel aberrations - deletions in chromosome 7 and 22 - that might play an important role in LPD disease. These findings might contribute to new insights to unravel the pathogenesis of LPD and develop further clinical treatments. © 2015 S. Karger AG, Basel.

Molecular analyses of 6 different types of uterine smooth muscle tumors: Emphasis in atypical leiomyoma

BACKGROUND

Uterine smooth muscle tumors (USMTs) constitute a group of histologic, genetic, and clinical heterogeneous tumors that include at least 6 major histologically defined tumor types: leiomyoma (ULM), mitotically active leiomyoma (MALM), cellular leiomyoma (CLM), atypical leiomyoma (ALM), uncertain malignant potential (STUMP), and leiomyosarcoma (LMS). Apart from ULM and LMS, the nature of these variants is not well defined.

METHODS

A total of 167 cases of different USMT variants were collected, reviewed, and diagnostically confirmed based on the World Health Organization and Stanford schemes. These included 38 cases of LMS, 18 cases of STUMP, 42 cases of ALM, 22 cases of CLM, 7 cases of MALM, and 40 cases of ULM. Molecular analysis included selected microRNAs (miRNAs), oncogenes, and tumor suppressors that are highly relevant to USMT.

RESULTS

Overall, 49% (17/35) of LMS cases and 7% (1/14) of STUMP cases died due to their USMT, but no deaths were attributed to ALM. miRNA profiling revealed that ALM and LMS shared similar miRNA signatures. P53 mutations and PTEN deletions were significantly higher in LMS, ALM, and STUMP compared with other USMT variants (P < .01). In contrast, MED12 mutations were extremely common in ULM and MALM (> 74%) but were significantly less common (< 15%) in CLM, ALM, STUMP, and LMS (P < .01).

CONCLUSION

Six types of USMT have different gene mutation fingerprints. ALM shares many molecular alterations with LMS. Our findings suggest that ALM may be a precursor lesion of LMS or have similar genetic changes during its early stage.

Recurrent chromosomal aberrations in intravenous leiomyomatosis of the uterus: high-resolution array comparative genomic hybridization study

Uterine intravenous leiomyomatosis (IVL) is a distinct smooth muscle neoplasm with a potential of clinical aggressiveness due to its ability to extend into intrauterine and extrauterine vasculature. In this study, chromosomal alterations analyzed by oligonucleotide array comparative genomic hybridization were performed in 9 cases of IVL. The analysis was informative in all cases with multiple copy number losses and/or gains observed in each tumor. The most frequent recurrent loss of 22q12.3-q13.1 was observed in 6 tumors (66.7%), followed by losses of 22q11.23-q13.31, 1p36.13-p33, 2p25.3-p23.3, and 2q24.2-q32.2 and gains of 6p22.2, 2q37.3 and 10q22.2-q22.3, in decreasing order of frequency. Copy number variants were identified at 14q11.2, 15q11.1-q11.2, and 15q26.2. Genes mapping to the regions of loss include CHEK2, EWS, NF2, PDGFB, and MAP3K7IP1 on chromosome 22q, HEI10 on chromosome 14q, and succinate dehydrogenase subunit B, E2F2, ARID1A KPNA6, EIF3S2 , PTCH2, and PIK3R3 on chromosome 1p. Regional losses on chromosomes 22q and 1p and gains on chromosomes 12q showed overlaps with those previously observed in uterine leiomyosarcomas. In addition, presence of multiple chromosomal aberrations implies a higher level of genetic instability. Follow-up polymerase chain reaction (PCR) sequencing analysis of MED12 gene revealed absence of G> A transition at nucleotides c.130 or c.131 in all 9 cases, a frequent mutation found in uterine leiomyoma and its variants. In conclusion, this is the first report of high-resolution, genome-wide investigation of IVL by oligonucleotide array comparative genomic hybridization. The presence of high frequencies of recurrent regional loss involving several chromosomes is an important finding and likely related to the pathogenesis of the disease.

Uterine cellular leiomyomata with chromosome 1p deletions represent a distinct entity

OBJECTIVE

This study aimed to determine whether 1p deletion defines a subset of cellular leiomyomata (CL), which is a hypercellular variant of uterine leiomyomata that may have delayed malignant potential, and to correlate this genetic change with clinical and pathologic characteristics including those present in uterine sarcomas.

STUDY DESIGN

Available CL cases at the Mayo Clinic (n = 101) and variant cases reported in another article (n = 16) were identified. Each case with sufficient tissue that met histologic criteria for CL when reviewed by a single pathologist underwent interphase fluorescence in situ hybridization to determine the presence of 1p deletion. Clinical characteristics of women with confirmed CL were compared on the basis of 1p deletion status using univariate analysis.

RESULTS

Of the Mayo Clinic cohort of histologically confirmed CL, 23% had deletion of 1p. Women with this subset of CL, when compared to those without 1p deletion, were more likely to be postmenopausal (P = .049) and their uteri tended to be heavier (P = .039) with a larger dominant leiomyoma (P = .030). The pathologic features associated with 1p deletion were high cellularity (P = .036) and hyaline necrosis (P = .047), which remained significant after inclusion of the CL cases from a previously published series.

CONCLUSION

Deletion of 1p occurs in approximately one-quarter of CL cases. This genetic alteration is potentially associated with clinicopathologic features that are present in uterine sarcomas, which suggests a distinct clinical entity that may have malignant potential. Our findings are particularly pertinent considering the increased preference for uterine-sparing options in leiomyoma treatment, suggesting assessment of 1p deletion status in CL may influence clinical surveillance decisions.

Genomic alterations in pulmonary adenocarcinoma in situ in an adolescent patient

Lung cancer is a rare event in the pediatric and adolescent population. To date, only a few case reports and small case series have been published, and little is known about the risk factors associated with this entity in children and adolescents. We describe a case of adenocarcinoma in situ in a 15-year-old adolescent girl with previous surgical treatment for malignant melanoma. We provide a detailed genomic characterization of this neoplasm by comparative genomic hybridization, genome-wide single-nucleotide polymorphism array, and fluorescence in situ hybridization analyses. We identify chromosomal regions with copy number changes and correlate the corresponding genes within these regions with the available literature in the area.

Genomic signatures predict poor outcome in undifferentiated pleomorphic sarcomas and leiomyosarcomas

Undifferentiated high-grade pleomorphic sarcomas (UPSs) display aggressive clinical behavior and frequently develop local recurrence and distant metastasis. Because these sarcomas often share similar morphological patterns with other tumors, particularly leiomyosarcomas (LMSs), classification by exclusion is frequently used. In this study, array-based comparative genomic hybridization (array CGH) was used to analyze 20 UPS and 17 LMS samples from untreated patients. The LMS samples presented a lower frequency of genomic alterations compared with the UPS samples. The most frequently altered UPS regions involved gains at 20q13.33 and 7q22.1 and losses at 3p26.3. Gains at 8q24.3 and 19q13.12 and losses at 9p21.3 were frequently detected in the LMS samples. Of these regions, gains at 1q21.3, 11q12.2-q12.3, 16p11.2, and 19q13.12 were significantly associated with reduced overall survival times in LMS patients. A multivariate analysis revealed that gains at 1q21.3 were an independent prognostic marker of shorter survival times in LMS patients (HR = 13.76; P = 0.019). Although the copy number profiles of the UPS and LMS samples could not be distinguished using unsupervised hierarchical clustering analysis, one of the three clusters presented cases associated with poor prognostic outcome (P = 0.022). A relative copy number analysis for the ARNT, SLC27A3, and PBXIP1 genes was performed using quantitative real-time PCR in 11 LMS and 16 UPS samples. Gains at 1q21-q22 were observed in both tumor types, particularly in the UPS samples. These findings provide strong evidence for the existence of a genomic signature to predict poor outcome in a subset of UPS and LMS patients.

An integrative genomic and transcriptomic analysis reveals potential targets associated with cell proliferation in uterine leiomyomas

Background

Uterine Leiomyomas (ULs) are the most common benign tumours affecting women of reproductive age. ULs represent a major problem in public health, as they are the main indication for hysterectomy. Approximately 40–50% of ULs have non-random cytogenetic abnormalities, and half of ULs may have copy number alterations (CNAs). Gene expression microarrays studies have demonstrated that cell proliferation genes act in response to growth factors and steroids. However, only a few genes mapping to CNAs regions were found to be associated with ULs.

Methodology

We applied an integrative analysis using genomic and transcriptomic data to identify the pathways and molecular markers associated with ULs. Fifty-one fresh frozen specimens were evaluated by array CGH (JISTIC) and gene expression microarrays (SAM). The CONEXIC algorithm was applied to integrate the data.

Principal Findings

The integrated analysis identified the top 30 significant genes (P<0.01), which comprised genes associated with cancer, whereas the protein-protein interaction analysis indicated a strong association between FANCA and BRCA1. Functional in silico analysis revealed target molecules for drugs involved in cell proliferation, including FGFR1 and IGFBP5. Transcriptional and protein analyses showed that FGFR1 (P = 0.006 and P<0.01, respectively) and IGFBP5 (P = 0.0002 and P = 0.006, respectively) were up-regulated in the tumours when compared with the adjacent normal myometrium.

Conclusions

The integrative genomic and transcriptomic approach indicated that FGFR1 and IGFBP5 amplification, as well as the consequent up-regulation of the protein products, plays an important role in the aetiology of ULs and thus provides data for potential drug therapies development to target genes associated with cellular proliferation in ULs.

Characterization of giant marker and ring chromosomes in a pleomorphic leiomyosarcoma of soft tissue by spectral karyotyping

Pleomorphic leiomyosarcoma of soft tissue is relatively rare and its cytogenetic and molecular genetic data are scarce. We present a case of pleomorphic leiomyosarcoma arising in the left thigh of a 60-year-old man. Fluorine-18-deoxyglucose positron emission tomography imaging showed a homogenously high uptake within the mass in the proximal left thigh (maximum standardized uptake value, 20.9). Following a core needle biopsy, wide resection of the tumor was performed. Histologically, the tumor was composed of a mixture of spindle cells, polygonal cells and bizarre giant cells forming interlacing bundles and a storiform pattern. Immunohistochemically, the tumor cells were positive for vimentin, smooth muscle actin and desmin. The MIB-1 labeling index was 19.7% in the highest spot. Cytogenetic analysis exhibited a complex karyotype with several numerical and structural alterations, including giant marker and ring chromosomes. Spectral karyotyping demonstrated that giant marker and ring chromosomes were composed of material from the X chromosome. Metaphase-based comparative genomic hybridization analysis showed high-level amplifications of 1q21-q25 and 12q13-q21 and gains of 1p31-p32, 10p11-p13, 17p11 and 19p13. The patient received postoperative adjuvant radiotherapy and doxorubicin-based chemotherapy. No local recurrence or distant metastasis was detected during a follow-up period of 19 months. The clinicopathological, cytogenetic and molecular genetic features of pleomorphic soft tissue leiomyosarcoma are discussed.

Increased risk of secondary uterine leiomyosarcoma in hereditary retinoblastoma

OBJECTIVE

In the US, second non-ocular malignancies are the primary cause of death in retinoblastoma survivors with the germline RB1 mutation. Soft tissue sarcomas are one of the most likely malignancies to pose a risk to these patients, with leiomyosarcoma (LMS) being the most common subtype. As our cohort is followed for a longer period, we discover new second malignancy risks for these patients.

METHODS

We estimated the risk for uterine leiomyosarcoma (ULMS) in a cohort of 1854 patients with retinoblastoma who were diagnosed at two US institutions from 1914 through 1996. The standardized incidence ratio and excess absolute risk were calculated by comparison with population data from the Connecticut Tumor Registry or from National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database. The cumulative risk at 50 years of age was also calculated.

RESULTS

Seven of 525 female hereditary retinoblastoma patients developed ULMS. Five of these patients were used in the risk analysis, resulting in an excess risk of 3.87 per 10,000 women. Among hereditary patients who developed ULMS the excess risk increases dramatically with age: to 20/10,000 for female hereditary retinoblastoma patients aged between 30 and 39 years, and to 27/10,000 for patients aged 40+ years.

CONCLUSION

There is a substantial excess risk of ULMS in female hereditary retinoblastoma patients. As more patients survive into their thirties, this number is likely to increase. These findings raise the question of early childbearing, screening and prophylactic measures in hereditary retinoblastoma patients: all issues that would benefit from confirmation from other retinoblastoma cohorts, to allow for better guided counsel of these patients.

Genome-wide analysis of loss of heterozygosity and copy number amplification in uterine leiomyomas using the 100K single nucleotide polymorphism array

PURPOSE

Uterine leiomyomas (fibroids) are benign smooth muscle tumors commonly found among reproductive-aged women. Though benign, these tumors are the leading indication for hysterectomies in the United States and cause significant morbidity. Despite the importance of this tumor in women's health, relatively little is known about the molecular etiology.

METHODS

In this study, we used the Affymetrix 100K single nucleotide polymorphism (SNP) chip to assess whether the pattern and frequency of genome-wide loss of heterozygosity (LOH) and copy number amplifications is associated with clinical heterogeneity.

RESULTS

Thirty-seven tumors with varying sizes and histology from eleven patients were analyzed. LOH was observed in 4/37 tumors (10.8%) and significantly associated with large-sized tumors (p<0.0014). Two tumors revealed hemizygosity on chromosome 7q, a region that has been consistently reported to have LOH. Additionally, we detected one novel region of LOH, 16p13.11 in one tumor (2.7%). Copy number amplifications were observed on all chromosomes; however, most were low-level amplifications and only detected in a single tumor. One region of amplification at 3p26.3 was detected in four tumors.

CONCLUSIONS

Despite the use of a high-density SNP platform, our results suggest that genome-wide LOH and copy number amplifications are infrequent events and generally do not determine clinical and histologic characteristics of this disease.

Proinflammatory and profibrotic mediators: principal effectors of leiomyoma development as a fibrotic disorder

Leiomyomas are believed to derive from the transformation of myometrial smooth muscle cells/connective tissue fibroblasts. Although the identity of the molecule(s) that initiate such cellular transformation and orchestrate subsequent growth is still unknown, conventional evidence indicates that ovarian steroids are essential for leiomyoma growth. Ovarian steroid action in their target cell/tissue is mediated in part through local expression of various growth factors, cytokines, and chemokines. These autocrine/paracrine molecules with proinflammatory and profibrotic activities serve as major contributing factors in regulating cellular transformation, cell growth and apoptosis, angiogenesis, cellular hypertrophy, and excess tissue turnover, events central to leiomyoma growth. This review addresses the key regulatory functions of proinflammatory and profibrotic mediators and their molecular mechanisms, downstream signaling that regulates cellular events that result in transformation, and commitments of specific cells into forming a cellular environment with a possible role in development and subsequent growth of leiomyomas.

Molecular profiling of endometrial malignancies

Molecular profiling of endometrial neoplasms reveals genetic changes in endometrial carcinomas that support the dualistic model, in which type I carcinomas are estrogen-dependent, low grade lesions and type II carcinomas are nonestrogen dependent and high grade. The molecular changes in type I endometrial carcinomas include mutations in PTEN, PIK3CA, KRAS, and β-catenin, along with microsatellite instability, whereas type II endometrial carcinomas are characterized by genetic alterations in p53, HER2/neu, p16, and E-cadherin. For endometrial neoplasms with a malignant mesenchymal component, C-MYC mutations and loss of heterozygosity are frequently seen in carcinosarcomas, and a fusion gene, JAZF1/JJAZ1, is distinctive for endometrial stromal sarcoma. In addition, p53 mutations may play an important role in tumorigenesis of undifferentiated endometrial sarcoma. These molecular changes can help in the diagnosis of endometrial neoplasms, as well as form the basis of molecular targeted therapy.

Synchronous presentation of uterine leiomyosarcoma and retroperitoneal liposarcoma: analysis by comparative genomic hybridization and review of the literature

Multiple primary malignant neoplasms are not uncommon, whereas 2 different types of primary sarcomas simultaneously presenting in 1 individual is quite unusual. We encountered a patient presenting with a uterine sarcoma and another retroperitoneal mass at the same time. These 2 tumors showed distinct pathologic and immunohistochemical features. The diagnosis of a synchronous presentation of a uterine leiomyosarcoma and a retroperitoneal sclerosing well-differentiated liposarcoma was rendered. Further study by comparative genomic hybridization showed unrelated genomic alterations of these 2 tumors. Nevertheless, other common genetic alterations such as balanced translocations, point mutations, or epigenetic modifications could still exist because of the limitation of findings by comparative genomic hybridization. In conclusion, both metastasis and multiple primary tumors should always be taken into consideration in differential diagnosis while encountering synchronous sarcomas.

Molecular Genetics of Mesenchymal Tumors of the Female Genital Tract

Mesenchymal tumors of the female genital tract are a heterogeneous group of neoplasms that can be classified based on cellular differentiation into 3 main groups: smooth muscle tumors, endometrial stromal tumors, and other differentiated and undifferentiated tumors. Genomic analysis techniques have revealed important genetic aberrations such as the t(7;17) translocation, resulting in JAZF1-JJAZ1 gene fusion, characteristic of endometrial stromal tumors. These analyses have demonstrated genetic complexity and heterogeneity in many mesenchymal tumor types. This article focuses on current understanding of the molecular genetics of mesenchymal tumors of the female genital tract, with emphasis on diagnostic and prognostic molecular features.

Uterine artery occlusion for the treatment of symptomatic fibroids: Endoscopic, radiological and vaginal approach

Uterine fibroids are the most common solid pelvic tumors in women. Although many fibroids seem to cause no symptoms, for some women they can have serious adverse effects and impact on quality of life. Common symptoms associated with fibroids include abnormal uterine bleeding, pelvic pressure and reproductive dysfunction. The past decade has witnessed highly sophisticated diagnostic and therapeutic technology for fibroids. The tools currently at our disposal permit greater management flexibility, which must be tailored to the individual clinical situation. Nonsurgical treatments include medical therapy and treatments interfering with the blood supply to the uterus or the fibroid; among the latest introduced are uterine artery embolization performed by the interventional radiologist and laparoscopic uterine occlusion performed by the gynaecologist. Even simpler is the non-incision temporary uterine clamp directed with Doppler and placed in the side fornices in the vagina.

Detection of novel copy number variants in uterine leiomyomas using high-resolution SNP arrays

Uterine leiomyomas (ULs) are benign monoclonal tumors originating from myometrial tissue in the uterus. Genetic pathways that lead to myometrial transformation into leiomyomas are largely unknown. Approximately 40% of ULs are karyotypically abnormal by G-banding; however, the remaining 60% of leiomyomas do not contain cytogenetically visible genomic rearrangements. Recent technological advances such as array based comparative genomic hybridization (array CGH) and dense single nucleotide polymorphism (SNP) arrays have enabled genome-wide scanning for genomic rearrangements missed by karyotype banding analysis. In the current study, we employed a high resolution SNP microarray on 16 randomly selected ULs and normal myometrium samples to detect submicroscopic (<5 Mb) chromosomal aberrations. The SNP array identified gene dosage changes in 56% of the fibroids (9/16), 25% of which (4/16) had aberrations >5 Mb, whereas 31% of which (5/16) contained only submicroscopic copy number changes (<5 Mb). We corroborated 3/5 submicroscopic changes using quantitative PCR, meaning that ultimately, 19% of our samples (3/16) were found to contain only submicroscopic changes. Novel submicroscopic aberrations on chromosomal segments 1q42.13, 11q13.1 and 13q12.13 and large, previously unreported deletions on 15q11.2-q23, 17p-q21.31 and 22q12.2-q12.3 were identified. Previously reported deletions on 1p, 3q, 7q, 13, and chromosome 14q were also noted. RHOU, MAP3K11 and WASF3 gene copy numbers were changed in the subset of leiomyomas with submicroscopic aberrations, and these genes have previously been implicated in tumorigenesis. Our findings support the hypothesis that a significant fraction of ULs without visible cytogenetic changes harbor submicroscopic genomic rearrangements which may in turn contribute to transformation of normal myometrial tissue into leiomyomas.

Indistinguishable genomic profiles and shared prognostic markers in undifferentiated pleomorphic sarcoma and leiomyosarcoma: different sides of a single coin?

Soft tissue sarcoma (STS) diagnostics and prognostics are challenging, particularly in highly malignant and pleomorphic subtypes such as undifferentiated pleomorphic sarcoma (UPS) and leiomyosarcoma (LMS). We applied 32K BAC arrays and gene expression profiling to 18 extremity soft tissue LMS and 31 extremity soft tissue UPS with the aim of identifying molecular subtype signatures and genomic prognostic markers. Both the gains/losses and gene expression signatures revealed striking similarities between UPS and LMS, which were indistinguishable using unsupervised hierarchical cluster analysis and significance analysis for microarrays. Gene expression analysis revealed just nine genes, among them tropomyosin beta, which were differentially expressed. Loss of 4q31 (encompassing the SMAD1 locus), loss of 18q22, and tumor necrosis were identified as independent predictors of metastasis in multivariate stepwise Cox regression analysis. Combined analysis applying loss of 4q31 and 18q22 and the presence of necrosis improved the area under receiver operating characteristic curve for metastasis prediction from 0.64 to 0.86. The extensive genetic similarities between extremity soft tissue UPS and LMS suggest a shared lineage of these STS subtypes and the new and independent genetic prognosticators identified hold promise for refined prognostic determination in high-grade, genetically complex STS.

Does comparative genomic hybridization reveal distinct differences in DNA copy number sequence patterns between leiomyosarcoma and malignant fibrous histiocytoma?

Leiomyosarcoma (LMS) is the third most common type of soft tissue sarcoma after malignant fibrous histiocytoma (MFH) and liposarcoma. Comparative genomic hybridization (CGH) has shown similar DNA copy number imbalances in LMS and MFH. It has been suggested that both tumors may correspond to different differentiation states of a single tumor entity and that a large proportion of MFHs could correspond to undifferentiated LMS. We report CGH results from 102 MFH and 82 LMS cases, as well as a subsequent clustering analysis. The distribution pattern of DNA copy number changes could not differentiate LMS from MFH, suggesting that most MFHs could represent an ultimate state of tumor progression of LMS. Even if an oncogenic pattern common to LMS and MFH is valid, the genes relevant to smooth muscle cell differentiation may reside in one or more chromosomal imbalances that are not shared by both tumor types. Further explorative analysis identified a small cluster of tumors (9% of the samples: 2 LMS and 10 MFH) characterized by the presence of high-level amplifications at 1p33 approximately p34.3, 17q22 approximately q23, 17q25 approximately qter, 19p, 22p, and 22q, and associated with a higher proportion of tumors located in the thigh (P=0.003) and with male sex (P=0.079).

Pathology of uterine malignancies

This overview covers epithelial, stromal and mesenchymal malignancies of the body of the uterus, excluding the cervix. The distinction of type I and type II endometrial adenocarcinoma with the morphological variants of this tumour is discussed and some molecular aspects are explored. The concept of carcinosarcoma representing a metaplastic adenocarcinoma of the endometrium that behaves more like a carcinoma than a sarcoma is explained. Some types of mixed epithelial and stromal neoplasm are described and contrasted with carcinosarcoma. The concept of stromal sarcoma and high-grade uterine sarcoma is described and an outline of malignant smooth muscle tumours of the uterus includes a description of smooth muscle tumours of uncertain malignant potential and worrying benign smooth muscle lesions.

Uterine leiomyosarcomas are characterized by high p16, p53 and MIB1 expression in comparison with usual leiomyomas, leiomyoma variants and smooth muscle tumours of uncertain malignant potential

AIMS

It has been suggested that p16 is overexpressed in uterine leiomyosarcomas in comparison with leiomyomas. In this study, p16 immunohistochemical expression was assessed in a variety of uterine smooth muscle tumours, including usual leiomyomas, leiomyoma variants, smooth muscle tumours of uncertain malignant potential (STUMPs) and leiomyosarcomas. The aim was to ascertain whether there are differences in p16 expression between these groups and whether p16 is of potential value in the assessment of problematic uterine smooth muscle neoplasms. p16 expression was also compared with that of p53 and MIB1.

METHODS AND RESULTS

Cases of usual leiomyoma (n = 10), leiomyoma variants (n = 27), STUMP (n = 4) and leiomyosarcoma (n = 22) were subject to p16, p53 and MIB1 immunohistochemistry. For p16, cases were evaluated with respect to both staining distribution and intensity. There was a statistically significant difference in p16 distribution (P < 0.001) and intensity (P = 0.001) between leiomyosarcomas and the other groups. There was no difference in p16 expression between usual leiomyomas, leiomyoma variants and STUMPs. There were also statistically significant differences in p53 (P = 0.014) and MIB1 (P < 0.001) immunoreactivity between leiomyosarcomas and the other groups.

CONCLUSIONS

p16 is overexpressed in uterine leiomyosarcomas compared with leiomyomas, benign leiomyoma variants and STUMPs, suggesting that p16 may be implicated in the pathogenesis of malignant uterine smooth muscle neoplasms. p16, in combination with p53 and MIB1, may be of value as an adjunct to morphological examination in the assessment of problematic uterine smooth muscle tumours, although further large-scale studies with follow-up are necessary to confirm this.

A micro-RNA signature associated with race, tumor size, and target gene activity in human uterine leiomyomas

Human uterine leiomyomas (ULMs) are the most common neoplasms of women. Many genes are dysregulated in ULMs and some of this dysregulation may be due to abnormal expression of micro-RNAs (miRNAs). In this study, 55 ULMs and matched myometrium were collected from 41 patients for microarray-based global miRNA expression analysis. Of 206 miRNAs examined, 45 miRNAs were significantly up- or down-regulated in ULMs in comparison to the matched myometrium (P < 0.001). The top five dysregulated miRNAs in ULMs are the let-7 family, miR-21, miR-23b, miR-29b, and miR-197. Four polycistronic clusters of miRNAs were either up- or down-regulated, but not in a mixed pattern, indicative of coordinated regulation of these miRNAs. Significance analysis revealed that subsets of miRNAs were strongly associated with tumor sizes and race. By prediction analysis we identified some important tumorigenic genes previously identified in ULMs that may be targeted by the dysregulated miRNAs. HMGA2 was identified as one of target genes of the let-7 family of miRNAs and has been found to be suppressed by let-7 in vitro. This article contains Supplementary material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.

Genetic heterogeneity among uterine leiomyomata: insights into malignant progression

Uterine leiomyomata (UL), also known as fibroids, are the most common pelvic tumors in women of reproductive age and are the primary indication for hysterectomy in the USA. Many lines of evidence indicate a strong genetic component to the development of these tumors. In fact, approximately 40% of UL have non-random, tumor-specific chromosome abnormalities which have allowed classification into well-defined subgroups (deletion of portions of 7q, trisomy 12 or rearrangements of 12q15, 6p21 or 10q22) as well as identification of candidate genes for UL predisposition. Although benign, UL have been linked to malignancy through two genomic regions on chromosome 1. Mutation of fumarate hydratase (FH) at 1q43 is known to cause the Mendelian syndromes of multiple cutaneous and uterine leiomyomata (MCL) and hereditary leiomyomatosis and renal cell cancer (HLRCC), and recently, FH mutations have been detected in some non-syndromic UL. In addition, transcriptional profiling suggests that loss of the short arm of chromosome 1 in cellular leiomyomata, an uncommon histological variant of UL, may account in part for the presumed yet rare malignant transformation of UL to uterine leiomyosarcoma.

Areas with benign morphologic and immunohistochemical features are associated with some uterine leiomyosarcomas

The pathogenesis of uterine leiomyosarcomas (LMS) is poorly understood. It is unknown if these tumors arise de-novo or from pre-existing leiomyomata (LM) or atypical leiomyomata. In this study, we evaluated morphologic heterogeneity within uterine LMS to identify possible precursor lesions. We reviewed 11 cases of total hysterectomy in which the final diagnosis was LMS. All slides from the grossly recognized tumor were evaluated for the degree of atypia and mitotic counts within the leiomyosarcomas. The slides with the lowest and highest mitotic count were stained with monoclonal antibody to p53, MIB-1 and ER/PR. The number of cells stained was subjectively assessed to nearest 5%, with 1% for rare positive cells. Morphologically benign tumor areas were identified in 5 of the 11 tumors. These areas showed <5 mitoses/10 HPF, with 1+ atypia in 4 cases and 1-2+ atypia in 1 case. No necrosis was seen by definition. Immunostains could be done in 4 of these 5 cases. These morphologically benign areas showed a p53 expression of 1% in each of the 4 cases, with low MIB-1 (5 to 15%) and high ER/PR expression (ER: 50-100%, PR: 10-100%). Morphologically malignant areas had 13 to 31 mitoses/10 HPF, 2+ to 3+ atypia, p53 expression of 70% to 100%, MIB-1 expression of 40% to 100%, ER expression of 1 to 100% and PR expression of 1 to 100%. The benign and malignant areas merged in all cases. Morphologic and immunohistochemical spectrum of changes from benign to malignant is seen in 50% of LMS. This raises the possibility of progression of some leiomyomata to LMS.

Positron emission tomography and leiomyomas: Clinicopathologic analysis of 3 cases of PET scan-positive leiomyomas and literature review

INTRODUCTION

Studies have suggested that PET scans can differentiate between leiomyomas and leiomyosarcomas. Our experience, however, shows that PET scan-positive smooth muscle tumors are not necessarily malignant.

CASE REPORTS

Three patients with cancer underwent PET imaging. In all three, the most worrisome finding was a PET scan-positive uterine tumor. After surgical extirpation, all three uterine tumors were found to be benign smooth muscle neoplasms.

DISCUSSION

To explore the potential reason these tumors were positive on PET imaging, we performed a detailed histopathologic and immunohistochemical study of all specimens. Pathologic evaluation revealed a leiomyoma, a cellular leiomyoma, and a stromomyoma. There was no association between an increased Ki67 (proliferative) index and positivity on PET imaging. Increased vascularity, however, appeared to be a feature common to the leiomyomas that were PET-positive.

Array Comparative Genomic Hybridization Reveals Distinct DNA Copy Number Differences between Gastrointestinal Stromal Tumors and Leiomyosarcomas

Leiomyosarcomas are spindle cell tumors showing smooth muscle differentiation. Until recently, most gastrointestinal stromal tumors (GIST) were also classified as smooth muscle tumors, but now GISTs are recognized as a separate entity, defined as spindle cell and/or epithelioid tumors localized in the gastrointestinal tract. Using microarray-based comparative genomic hybridization (array CGH), we have created a detailed map of DNA copy number changes for 7 GISTs and 12 leiomyosarcomas. Considerable gains and losses of chromosomal segments were observed in both tumor types. The most frequent aberration observed in GISTs was loss of chromosomes 14 and 22, with minimal recurrent regions in 14q11.2-q32.33 (71% of the tumors) and 22q12.2-q13.31 (100%). In leiomyosarcomas, frequent loss of chromosome 10 and 13q was observed, with minimal recurrent regions in 10q21.3 (75%) and 13q14.2-q14.3 (75%). Recurrent high-level amplification of 17p13.1-p11.2 was detected in leiomyosarcomas. Expression profiling using cDNA microarrays revealed four candidate genes in this region with high expression (AURKB, SREBF1, MFAP4, and FLJ10847). Altered expression of AURKB and SREBF1 has been observed previously in other malignancies. Hierarchical clustering of all samples separated GISTs and leiomyosarcomas into two distinct clusters. Statistical analysis identified six chromosomal regions, 1p36.11-p13.1, 9q21.11-9q34.3, 14q11.2-q23.2, 14q31.3-q32.33, 15q24.3-q26.3, and 22q11.21-q13.31, which were significantly different in copy number between GISTs and leiomyosarcomas. Our results show the potential of using array comparative genomic hybridization to classify histologically similar tumors such as GISTs and leiomyosarcomas.

Do DNA copy number changes differentiate uterine from non-uterine leiomyosarcomas and predict metastasis?

DNA copy number changes were investigated in 51 (19 uterine and 32 nonuterine) primary leiomyosarcomas by comparative genomic hybridization. The aim was to evaluate whether true biological differences exist between uterine and nonuterine leiomyosarcoma and whether changes revealed by comparative genomic hybridization have prognostic value. Genomic imbalances were found in 48 (94%) cases. The most frequent DNA copy number changes were losses in 10q (35%), 13q (57%), and 16q (41%), gains in 1q (41%), and gains and high-level amplifications in 17p (39%). Gains were nearly as frequent as losses in both uterine and nonuterine leiomyosarcoma. Correlation-based tree modeling revealed two clusters that segregated significantly a group of uterine (gains at 1q11-q24) and a group of nonuterine (losses at 13q14-q34, 16q11.1-q24, and 10q21-q26) cases. The nonuterine cluster was associated with subcutaneous origin and a trend toward increased metastasis-free survival. Further explorative analyses identified aberrations associated with shorter metastasis-free survival time, including losses at 2q32.1-q37 and gains at 8q24.1-q24.3, whereas the cases with losses at 6cen-p25 showed longer metastasis-free survival time.

Comparative genomic hybridization study of perivascular epithelioid cell tumor: molecular genetic evidence of perivascular epithelioid cell tumor as a distinctive neoplasm

Perivascular epithelioid cell tumor (PEComa) is a neoplasm composed chiefly of HMB-45-positive epithelioid cells with clear to granular cytoplasm and a perivascular distribution. Such tumors have been reported in different organs under a variety of designations. The cytogenetic features of these neoplasms have not been well studied. We collected 9 tumors (5 of kidney, 1 of prostate, 1 of urinary bladder, 1 of the pelvic cavity soft tissue, and 1 of uterus) from 8 patients, including one patient with tuberous sclerosis complex. The paraffin blocks of tumor tissue were submitted for comparative genomic hybridization analyses. Gross chromosomal aberrances were observed in all cases. The frequent imbalances were losses on chromosome 19 (8 cases), 16p (6 cases), 17p (6 cases), 1p (5 cases), and 18p (4 cases) and gains on chromosome X (6 cases), 12q (6 cases), 3q (5 cases), 5 (4 cases), and 2q (4 cases). The frequent deletion of 16p in which TSC2 gene is located indicates the oncogenetic relationship of PEComas with angiomyolipoma as a TSC2-linked neoplasm. From a molecular genetic perspective, the recurrent chromosomal alterations in both renal and extrarenal tumors further support the concept of PEComa as a distinctive tumor entity regardless of anatomic location.

Clinical Features of Myomas

Uterine myomas are the most common solid pelvic tumors in women and the primary indication for hysterectomy. Most of the myomas are asymptomatic. The most common symptoms associated with uterine myomas are abnormal uterine bleeding and pelvic discomfort mostly caused by the mass effect. Vaginal bleeding may lead to iron deficiency anemia. Uterine myomas have a significant role in reproductive dysfunction, although a causal relationship between infertility and intramural or subserosal myomas not disturbing the uterine cavity has not been established clearly. Nevertheless myomas, especially the tumors distorting the uterine cavity, are associated with infertility and spontaneous miscarriage. In addition, the myomas may be the potential cause for numerous obstetric complications, especially if they are located adjacent to placenta. The transformation of myomas to leiomyosarcomas is a very rare event. Leiomyosarcomas may be suspected in postmenopausal women with rapidly growing symptomatic solid pelvic mass. Despite the high prevalence of these tumors, there is paucity of data available regarding the natural clinical history of myomas.

Differential diagnosis of gastrointestinal leiomyoma versus gastrointestinal stromal tumor

INTRODUCTION

Strategies for the diagnosis of tumors arising in the intestinal muscular wall are rapidly evolving. Immunoreactivity for CD117 (KIT) usually supports the diagnosis of gastrointestinal stromal tumor (GIST), but a small subset of GISTs lacks KIT expression. In these cases the differential diagnosis of KIT-negative GIST versus one of their morphological mimics is difficult and bears critical implications for therapeutic management.

CASE REPORT

Here, we report a case of a KIT-negative smooth muscle cell tumor of the colon in a 21-year-old man with the clinical appearance of GIST. Mutations of the KIT and platelet-derived growth factor receptor alpha (PDGFRA) gene could be ruled out. No chromosomal imbalances characteristic of GIST were found. However, cytogenetic analysis revealed losses at 7q, which has previously been reported in cases of uterine leiomyoma.

DISCUSSION

We discuss current approaches to the differential diagnosis of true gastrointestinal smooth muscle cell tumor versus GIST.

Analysis of fumarate hydratase mutations in a population-based series of early onset uterine leiomyosarcoma patients

Germline mutations in fumarate hydratase (FH) gene at 1q43 predispose to hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. In HLRCC, the most common clinical features are leiomyomas of the skin and uterus, and in a subset of the families, renal cell cancer (RCC) and uterine leiomyosarcoma (ULMS) occur frequently at young age. This study was conducted to evaluate the possible contribution of FH mutations in a population-based series of early onset (< or = 45 years) ULMSs. Eighty-one cases were identified through the national cancer registry, and samples from 67 cases (83%) were available for FH mutation screening and analysis of allelic imbalance (AI) at the FH locus. Seventeen percent of tumors showed AI. In the mutation analysis, a novel missense mutation K424R was found. The mutation was also found from the patient's normal tissue. To study whether this variant has functional consequences, FH enzyme activity assay was performed in a cell model. The activity of the mutated protein was significantly reduced as compared to wild type (p = 0.009). This study shows that FH germline mutations can occur in seemingly nonsyndromic cases of ULMS (1/67, 1.5%). It appears that on the population level hereditary FH defects do play a role in pathogenesis of sporadic early onset ULMSs, albeit rarely.

Loss of DNA copy number of 10q is associated with aggressive behavior of leiomyosarcomas: a comparative genomic hybridization study

Leiomyosarcomas (LMS) account for 10-20% of all soft tissue sarcomas. We analyzed 10 primary, 5 metastatic, and 2 recurrent extrauterine LMS. Genomic imbalances were detected in 15 out of the 17 tumors. The most common regions of loss were 13q (59%, 10 of 17), 10q (59%, 10 of 17), 2q (35%, 6 of 17), and 16q (29%, 5 of 17). The most common region of gain was 5p (35%, 6 of 17). High-level gain of DNA copy number was detected in 6p and 17p. Loss of function of tumor suppressor genes or the activation of oncogenes (or both of these factors) resulting from these copy number changes might play an important role in the development of extrauterine LMS. Large tumors and tumors with metastasis showed 10q deletions. Gain of 5p was detected only in G3 tumors. These findings are consistent with our earlier study on uterine LMS and indicate that loss of 10q and gain of 5p are associated with an aggressive behavior of LMS. A larger series of cases is needed to confirm these results.

Prognostic importance of vascular endothelial growth factor and its receptors in the uterine sarcoma

Vascular endothelial growth factor (VEGF) and its receptors play an important role in tumor progression; however, there is no report regarding this factor in uterine sarcoma. Thirty-nine patients with uterine sarcoma, 14 carcinosarcomas, 4 endometrial stromal sarcomas, and 21 leiomyosarcomas, were studied. By immunohistochemical staining, VEGF was not detected in normal uterine smooth muscle, but VEGF receptor-1 (flt-1) and VEGF receptor-2 (flk-1) were observed in 14 and 4 of 14 normal smooth muscles, respectively. Of 39 sarcomas, 25 expressed VEGF, and 38 and 34 sarcomas expressed flt-1 and flk-1 at various intensities, respectively. The staining intensity of VEGF, flt-1, and flk-1 was significantly higher in sarcoma than in normal uterine smooth muscle, but that of phospho-flt-1 (p-flt-1) was significantly lower in sarcoma than in normal uterine smooth muscle. When sarcomas were divided into two groups according to staining intensity, a significant difference in survival curves was observed in only p-flt-1 of leiomyosarcoma (P= 0.008), and in all sarcomas, a lower survival curve was also observed in the high staining intensity group than in the low staining intensity group, although there was no significant difference (P= 0.102). In conclusion, VEGF and its receptors are suggested to be involved in progression of uterine sarcoma, but only the p-flt-1 level significantly affected the survival of leiomyosarcoma patients.