CD10 is a sensitive and diagnostically useful immunohistochemical marker of normal endometrial stroma and of endometrial stromal neoplasms

AIMS: The CD10 antigen is expressed in acute lymphoblastic leukaemia and follicle centre cell lymphoma. A recent study investigating the expression of CD10 in a wide range of non-haematopoietic neoplasms found positive staining in a small number of endometrial stromal sarcomas as well as in normal endometrial stroma. The present study aimed to ascertain whether CD10 positivity is indeed found in normal endometrial stroma and endometrial stromal neoplasms. Staining of a range of tumours which can be confused morphologically with endometrial stromal neoplasms was also undertaken to ascertain whether antibodies against CD10 are of value in a diagnostic sense. METHODS AND RESULTS: Neoplasms included in the study were endometrial stromal nodule (n=1), low-grade endometrial stromal sarcoma (ESS) (n=13), high-grade ESS (n=6), mixed endometrial stromal-smooth muscle tumour (n=1), uterine cellular leiomyoma (n=10), uterine leiomyosarcoma (n=5), adult granulosa cell tumour (AGCT) (n=10), undifferentiated endometrial carcinoma (n=6), uterine carcinosarcoma with an endometrial stromal component (n=1) and type II uterine mesenchymal tumour with sex cord-like elements (n=1). Cases of proliferative (n=5), secretory (n=5) and atrophic (n=3) endometrium were also stained. There was positive staining of stroma but not of glands in all cases of non-tumorous endometrium. There was positive staining of the endometrial stromal nodule and of all low-grade ESS. Staining in these varied but was often diffuse and of moderate to strong intensity. There was positive staining of four of six high-grade ESS, but this was usually focal. There was also positive staining of the endometrial stromal component in the mixed endometrial stromal-smooth muscle tumour and in the uterine carcinosarcoma. Most cellular leiomyomas were completely negative although three exhibited weak positivity. There was some positivity, usually focal or weak, of three of five leiomyosarcomas. Most AGCT and undifferentiated carcinomas were completely negative although one case of each exhibited focal staining. There was focal staining of the type II uterine mesenchymal tumour with sex cord-like elements. CONCLUSION: CD10 is a reliable and sensitive immunohistochemical marker of normal endometrial stroma. Positivity, which is often strong and/or diffuse is found in endometrial stromal nodules and low-grade ESS. Positive staining with CD10, when strong and diffuse, may be useful in distinguishing these tumours from histological mimics, especially cellular leiomyoma and AGCT which are generally negative. In this situation, CD10 should be used as part of a panel which might include desmin and alpha-inhibin depending on the differential diagnosis considered. Positive staining with CD10 in a high-grade uterine sarcoma which is negative with muscle markers might indicate endometrial stromal differentiation and identify a group of neoplasms which it is correct to diagnose as high-grade ESS rather than undifferentiated uterine sarcoma.     

Cytogenetic and molecular aberrations in endometrial stromal tumors

Endometrial stromal tumors (ESTs) are rare uterine mesenchymal tumors, comprising <10% of all uterine mesenchymal neoplasms. The latest World Health Organization classification divides endometrial stromal tumors into 3 categories based on morphologic features: endometrial stromal nodule (ESN), low-grade endometrial stromal sarcoma, and undifferentiated endometrial sarcoma. Specific cytogenetic aberrations and molecular genetic alterations have recently been identified in endometrial stromal tumors, providing insights into their molecular biology, potential diagnostic markers, and possible therapeutic targets. Currently, recurrent chromosomal rearrangements resulting in gene fusion play a substantive role in the pathogenesis of endometrial stromal nodules, endometrial stromal sarcomas, and a small subset of undifferentiated endometrial sarcomas. Loss of heterozygosity of tumor suppressor genes and deregulation of the Wnt signaling pathway have also been implicated in EST tumorigenesis. In this review, we summarize the recent advances in the molecular pathology of endometrial stromal tumors.     

子宫内膜间质肉瘤9例临床病理分析

目的 探讨子宫内膜间质肉瘤(endometrial stromal sarcoma,ESS)的临床病理特征、诊断、鉴别诊断及预后.方法 对9例ESS患者进行临床、病理资料分析、免疫组化检测及随访.结果 患者年龄39～64岁,中位46.3岁.临床主要表现为阴道流血及子宫增大/占位.肿瘤直径2.3～11 cm,平均4.6 cm.光镜下8例呈低度恶性子宫内膜间质肉瘤(low grade endometrial stromal sarcoma,LGESS),均由类似增殖期子宫内膜间质肿瘤细胞构成,细胞密集,异型性不明显,呈不规则舌状或岛状浸润肌层,并伴较多薄壁螺旋小血管;1例为高度恶性子宫内膜间质肉瘤/未分化子宫内膜肉瘤(high grade endometrial stromal sarcoma/undifferentiated endometrial sarcoma,HGESS/UES),肿瘤细胞直接替代子宫肌层,具有明显的细胞异型性,无LGESS常见的螺旋小血管.免疫组化检测显示肿瘤细胞CD10、vimentin均阳性,PR、ER大部分阳性,SMA和desmin及h-Caldesmon为极少数局灶阳性,S-100、CD34均阴性.术后随访7例(平均53个月),只有1例HGESS/UES死亡.结论 ESS是女性生殖道很少见的一种恶性肿瘤,恶性度相差很大.确诊主要依靠其临床病理特点,并辅以免疫组化标记综合分析.诊断时要与子宫内膜间质结节、平滑肌肿瘤、低分化癌等鉴别.     

Inverse correlation of secreted frizzled-related protein 4 and beta-catenin expression in endometrial stromal sarcomas

Endometrial stromal sarcomas are rare uterine tumours. Whereas the histology and immunohistochemistry of these tumours are well documented, almost nothing is known about the molecular mechanisms involved in their pathogenesis. To characterize the genes altered in these malignancies, a genome-wide cDNA library was generated by suppression subtractive hybridization and a set of differentially expressed clones was isolated. These were then used to produce custom-spotted cDNA arrays. Genes deregulated in endometrial stromal sarcomas were identified by cDNA array hybridization and were confirmed by quantitative real-time PCR analyses and in situ hybridization. Following cDNA array analysis, more than 300 genes deregulated in endometrial stromal sarcoma were selected and sequenced. Among the most significantly deregulated genes were those of secreted frizzled-related proteins (SFRPs), in particular secreted frizzled-related protein 4 (SFRP4). SFRPs are putative modulators of the Wnt-signalling pathway and play a role in different cellular events including cell proliferation. Compared with normal endometrium, the expression of SFRP4 was decreased in both low-grade endometrial stromal sarcoma (ESS; n = 10) and undifferentiated endometrial sarcoma (UES; n = 4), being lower in the latter more aggressive form. These results were verified on paraffin wax-embedded tissue by quantitative real-time PCR analysis and in situ hybridization. Furthermore, the expression of beta-catenin, an important component of the Wnt-signalling pathway, was regulated in an opposite manner to SFRP4, being particularly increased in undifferentiated sarcomas. The activation of the Wnt-signalling pathway was additionally supported by the immunohistochemical demonstration that beta-catenin was translocated to the nucleus in UES. SFRP4 may therefore be a putative tumour suppressor involved in deregulation of the Wnt pathway and in the pathogenesis of ESS and UES.     

New developments in endometrial stromal sarcoma

Endometrial stromal tumours have been recently reclassified in the WHO 2014 Classification due to the discovery of new genetic fusions. This has enabled the subdivision of previously described undifferentiated endometrial sarcomas into the molecularly-defined high grade endometrial stromal sarcoma (HG ESS) and undifferentiated uterine sarcoma (UUS). In this review, we discuss the discoveries behind the 2014 Classification and its rationale, and give practical tips for diagnosis of these neoplasms, as well as discussing the differential diagnoses that one may consider.     

Endometrial stromal sarcoma: clinicopathological and immunophenotype study of 18 cases

Malignant tumors of the uterine corpus are uncommon. They originate from the endometrial stroma, smooth muscle, blood vessels, or from a mixture of them. The objective of this article was to know the frequency and the clinical, morphologic, and immunophenotype characteristics of the endometrial stromal sarcoma (ESS). We reviewed the cases of ESS observed from 2002 to 2008 at the Pathology Unit of the General Hospital of Mexico. The following data were analyzed: age, clinical stage, degree of differentiation, and immunophenotype. We found 18 cases, and the average age of patients was 48.6 years; 66% were in clinical stages 1 and 2. Fifteen cases (83.3%) were classified as low-grade sarcomas and 3 (16.6%) as high-grade or undifferentiated sarcomas. We determined immunohistochemical markers in 17 cases; receptors to estrogens were positive in 5 (29.4%) and to progesterone in 9 (52.9%). CD10 was expressed in 10 (58.8%) and p53 in 11 cases (64.7%). Two cases were associated to primary tumors of the ovary (papillary cystadenocarcinoma). In conclusion, ESS was present at 0.6% in our institution; and most were low grade. Expression of markers, such as p53, CD10, and hormonal receptors, was positive.     

Mesenchymale Uterustumoren

Uterine stromal neoplasms are classified into endometrial stromal nodules and stromal sarcomas, as well as undifferentiated sarcomas. The two former groups demonstrate identical histological composition, consisting of small monomorphous cells with scant cytoplasm and round nuclei and typically contain numerous arteriolar-type vessels. Stromal tumors are distinct from stromal nodules by virtue of their myometrial and vascular invasion. Undifferentiated sarcomas consist of polymorphic cells and lack any cytological similarity to the stroma of normal proliferative endometrium. There is no smooth or striated muscle differentiation. Adenosarcomas are mixed neoplasms with a low grade stromal sarcoma component containing benign glands, which are surrounded by condensed neoplastic stroma. Typical uterine tumors resembling ovarian sex cord tumors (UTROSCT Type2) show predominant sex cord differentiation in a well circumscribed nodule. Focal sex cord differentiation may occur in stromal nodules and stromal sarcomas (UTROSCT Type2).     

Molecular genetic changes in epithelial, stromal and mixed neoplasms of the endometrium

Endometrial carcinoma, endometrial stromal tumours and mixed malignant mesodermal tumours (MMMT) develop along distinctive molecular genetic pathways. Two distinctive types of endometrial carcinoma are distinguished, type I and type II, which develop along distinctive pathways and show different clinical behaviour and histological features. Type I carcinomas show endometrioid histology, are oestrogen-related and develop from atypical endometrial hyperplasia. The molecular tumorigenesis is comparable to colorectal carcinoma with a step-like progression and an accumulation of genetic alterations. Alterations of PTEN, K-Ras mutations and microsatellite instability are frequent and early events in type I carcinoma, whereas p53 mutations occur during progression to grade 3 carcinoma. Serous and clear cell carcinomas are considered type II carcinomas which are mostly unrelated to oestrogen. p53 mutations occur in almost all serous carcinomas and seem to occur early, leading to massive chromosomal instability and rapid tumour progression. Gene expression profiling has supported this dualistic model of endometrial carcinoma. There is evidence of molecular differences between serous and clear cell carcinomas as well as between endometrioid carcinomas with and without microsatellite instability. A dualistic model of tumorigenesis may be also suggested for endometrial stromal tumours. Endometrial stromal sarcomas (ESS; type I endometrial sarcoma) are oestrogen-related and seem to develop from endometrial stromal nodules (ESN). They are histologically and genetically distinct from undifferentiated endometrial sarcoma (UES) which seem to be mostly unrelated to oestrogen (type II endometrial sarcoma). ESS and ESN share the fusion gene JAZF1/JJAZ1 caused by a t(7;17)(p15;q21) translocation, whereas UES lacks a distinctive molecular alteration so far. In MMMT, which is considered a metaplastic carcinoma, p53 alteration occurs early, before clonal expansion and acquisition of genetic diversity during progression.     

Uterine stromal neoplasms: a clinicopathologic and DNA flow cytometric correlation

Twenty-five uterine stromal neoplasms (five stromal nodules and 12 low-grade and eight high-grade stromal sarcomas) were studied to determine the correlation between clinicopathologic features, flow cytometric tumor DNA content and proliferative fraction, and patient outcome. Fifteen of the 20 sarcomas (five of them high grade) were confined to the uterus (stages I and II); the other five (two low grade and three high grade) extended outside the uterus (stages III and IV). Stromal nodules and low-grade sarcomas manifested diploid DNA content and low proliferative index. All stromal nodules and the majority of low-grade sarcomas pursued a benign clinical course. Two cases of low-grade sarcoma ran a malignant course; both patients had high-stage disease. Three of the high-grade sarcomas were diploid and five were aneuploid. All eight neoplasms demonstrated high proliferative index and seven ran a malignant course (four of five were stage I and three of three were stage IV). Three high-grade stage I tumors had a low mitotic rate but a high proliferative index and ran an aggressive course. All high-stage sarcomas were clinically aggressive, irrespective of their histologic classification or DNA characteristics. The proliferative index by flow cytometry may offer an objective adjunct in predicting the aggressive potential of a subset in low-stage neoplasms.     

Uterine mesenchymal tumours: recent advances

Almost all uterine mesenchymal tumours have been historically classified as either smooth muscle or endometrial stromal neoplasms. Recent application of molecular techniques has identified numerous lesions with distinctive genetic abnormalities and clinicopathological characteristics. Newly discovered uterine sarcoma subtypes include high-grade endometrial stromal sarcomas with BCOR genetic abnormalities, fibrosarcoma-like uterine sarcomas with NTRK rearrangements and COL1A–PDGFRB fusions, as well as undifferentiated uterine sarcomas with SMARCA4 mutations. Novel PLAG1 and PGR fusions have been identified in subsets of myxoid and epithelioid leiomyosarcomas. Some uterine tumours resembling ovarian sex-cord tumour harbour GREB1 and ESR1 rearrangements. Histological and immunophenotypical features as well as underlying genetic abnormalities defining these lesions are discussed.     

Comparative clinicopathologic and immunohistochemical analysis of uterine sarcomas diagnosed using the World Health Organization classification system

Uterine sarcomas are rare tumors that account for 3% to 7% of uterine cancers. Their histopathologic classification was revised by the World Health Organization (WHO) in 2003. The objectives of this study were to determine the frequency of different subtypes of uterine sarcoma applying the WHO criteria to a series of cases, compare the outcome of patients with different subtypes, and compare their immunoprofiles using a panel of immunomarkers. Thirty-four uterine sarcomas were identified for a 20-year period (1988-2008). Eighteen benign tumors of smooth muscle or endometrial stromal origin served as a comparison group. A tissue microarray was prepared and immunostaining performed for 10 selected oncoproteins involved in cell proliferation (Ki-67, P53, p16, and phosphatase and tensin homolog [PTEN]), cell differentiation (CD10, h-caldesmon, estrogen receptor, and progesterone receptor), and apoptosis (bcl-2 and Twist). Hierarchical clustering analysis of the immunohistochemical results was performed. The uterine sarcomas were classified as follows: 20 leiomyosarcomas, 9 endometrial stromal sarcomas, and 5 undifferentiated endometrial sarcomas. The outcome for patients with uterine sarcoma was poor, irrespective of histologic type, even for those with stage I tumors. Of the patients with follow-up available, 12 (67%) of 18 with leiomyosarcoma, 4 of 5 with undifferentiated sarcoma, and 4 of 7 with endometrial stromal sarcoma experienced recurrence and 8 patients with high-grade sarcomas died of tumor. In our series, most uterine sarcomas were leiomyosarcomas. Comparison was made between leiomyosarcomas that recurred and those with a favorable outcome and 3 patients with leiomyosarcoma without evidence of recurrence on long-term follow-up had tumors that were negative/low expressors of Ki-67, p53, p16, and Twist, with strong expression of bcl-2. A subset of undifferentiated endometrial sarcomas composed of cells with uniform nuclei may be a separate entity from those with nuclear anaplasia and may be related to low-grade endometrial stromal sarcomas. It may be possible to identify a subset of leiomyosarcomas with a favorable prognosis based on staining with a panel of immunomarkers for cell proliferation and apoptosis.     

Endometrial stromal tumors: an update on a group of tumors with a protean phenotype

Endometrial stromal tumors are reviewed with emphasis on their wide morphologic spectrum and problems in differential diagnosis, highlighting issues that have received particular attention in the recent literature. These neoplasms are divided into two major categories--endometrial stromal nodules and endometrial stromal sarcomas--a distinction made on the basis of the lack of significant infiltration at the periphery of the former. The division of endometrial stromal sarcomas into low-grade and high-grade categories has fallen out of favor and the designation endometrial stromal sarcoma is now considered best restricted to neoplasms that were formally referred to as "low-grade" stromal sarcoma. Endometrial sarcomas without recognizable evidence of a definite endometrial stromal phenotype, designated poorly differentiated "endometrial sarcomas," are almost invariably high grade and often resemble the mesenchymal component of a malignant mullerian mixed tumor. Two features of endometrial stromal tumors that may cause confusion are smooth muscle differentiation and epithelial patterns. Cases in the former category often have a characteristic "starburst" pattern of collagen formation. The most common epithelial patterns resemble those seen in ovarian sex-cord stromal tumors. Much less common is endometrioid gland differentiation. Some endometrial stromal tumors have a prominent fibrous or myxoid appearance and the myxoid tumors should be distinguished from myxoid leiomyosarcoma. Other unusual features of endometrial stromal tumors are also discussed. Lesions in the differential diagnosis of uterine endometrial stromal neoplasms include highly cellular leiomyoma, cellular intravenous leiomyomatosis, adenomyosis with sparse glands, metastatic carcinoma, and lymphoma. Endometrial stromal sarcomas at extrauterine sites may be primary or metastatic from a uterine tumor, the latter sometimes being occult and difficult to definitively establish, particularly if there is a history of a remote hysterectomy for "leiomyomas." Endometrial stromal sarcomas of the ovary, whether primary or metastatic, may be difficult to distinguish from ovarian sex-cord stromal tumors. Extragenital endometrial stromal sarcomas may be confused with diverse lesions such as gastrointestinal stromal tumors, hemangiopericytoma, lymphangiomyomatosis, or mesenchymal cystic hamartoma of the lung. Immunohistochemistry may play a role in evaluating these tumors and in some instances establishing the diagnosis although conventional light microscopic analysis suffices in the majority of cases. The unusual tumor, the "uterine tumor resembling an ovarian sex-cord tumor," is also considered in this review as it is almost certainly of endometrial stromal derivation in many cases. These neoplasms may have a striking resemblance to granulosa cell tumors or Sertoli cell tumors, including those with a retiform pattern, and have recently been shown to be frequently inhibin positive.     

Immunohistochemical study of uterine stromal sarcoma and rhabdomyosarcoma

The cytoplasmic filament composition of two pure high-grade endometrial stromal sarcomas and five pure endometrial rhabdomyosarcomas was studied using the immunoperoxidase avidin-biotin method. Ultrastructural correlates were performed on the same tissues. While four of the seven tumors presented as high-grade undifferentiated neoplasms, they were readily categorized on the basis of immunocytochemical findings in which the five rhabdomyosarcomas were positive for muscle-specific actin (HHF 35) and the two stromal sarcomas were positive for vimentin only. Ultrastructure on the HHF 35-positive cases showed the presence of thick filaments and Z-band material, whereas the other tumors showed no cytoplasmic differentiation. Muscle-type actin differs stromal cells, and is useful when used in conjunction with a panel of antibodies in the categorization of undifferentiated endometrial sarcomas.     

Expression of CD10 in malignant müllerian mixed tumors and adenosarcomas: an immunohistochemical study.

CD10 has been demonstrated to be positive in endometrial stromal sarcoma (ESS) and thus is useful in establishing the diagnosis, but its expression in malignant müllerian mixed tumor (MMMT) and müllerian adenosarcoma remains to be clarified. In this study, 12 cases of MMMT (9 uterine, 2 tubal, and 1 metastatic), 6 cases of müllerian adenosarcoma (three corporeal, two cervical, and one tubal), and 7 cases of primary uterine sarcomas had their tissues examined immunohistochemically for expression of CD10, desmin, myoglobin, alpha-smooth muscle actin (SMA), and cytokeratin. Of the primary uterine sarcomas, two were primary rhabdomyosarcomas (one cervical and one corporeal), two were ESSs, two were high-grade leiomyosarcomas, and one was a high-grade endometrial sarcoma. Sarcomatous components in all cases of MMMT and müllerian adenosarcoma, as well as all uterine sarcomas, were positive for CD10, showing moderate to marked staining intensity with varying distribution except in one MMMT, which showed weak and very focal staining. In four MMMTs, three adenosarcomas, and one rhabdomyosarcoma, myoglobin- and/or desmin-positive rhabdomyoblastic cells were positive for CD10. The immunoreactivity for CD10 showed the same distribution for alpha-SMA and myoglobin in three and two MMMTs, respectively. In five cases of MMMT, carcinomatous components were focally positive for CD10, and in two cases small populations of round or short spindle cells in sarcomatous components were positive for CD10, alpha-SMA, and cytokeratin (CAM5.2). These results indicate that CD10 expression is not restricted to ESS but can be positive in MMMT and müllerian adenosarcoma as well as in a variety of uterine tumors including high-grade leiomyosarcoma and rhabdomyosarcoma. CD10 expression might be one of the characteristics of müllerian system-derived neoplastic mesenchymal cells.     

Endometrial stromal sarcoma with endometrioid adenocarcinoma of the uterus: a case report

Endometrial stromal sarcoma (ESS) is a rare malignant neoplasm of the uterus. We report the first case of undifferentiated ESS (UES) coexistent with grade 1 endometrioid adenocarcinoma in a 73-year-old female who presented with irregular vaginal bleeding for 4 days after menopause 20 years. Imaging examination including Magnetic Resonance Imaging (MRI) demonstrated multi-node reflection in uterine cavity without metastatic lesions, and the endometrium essentially normal. Grossly, a grey-red breakable polypoid tumor of 4.5 × 3.0 ×2.0 cm was recognized in the posterior uterine wall with surrounding slight rough endometrium. Microscopically, the tumor was composed of a larger component of undifferentiated stromal sarcoma that was distinct from a smaller endometrioid adenocarcinoma. The separate components of the tumor could be supported in immunohistochemical studies. There was no sign of recurrence for postoperative 6 months.     

Endometrial stromal sarcomas: immunohistochemical, electron microscopical and cytogenetic findings in two cases

 Uterine sarcomas are approximately 3% of all malignant uterine corpus tumours. Of these, the tumours that originate solely in the stromal elements of the uterine wall are infrequent and have not been well characterized cytogenetically. We report two cases of endometrial stromal sarcomas (ESS), one low grade and one high grade, diagnosed by conventional histology, immunocytochemistry, electron microscopy and cytogenetics. Morphologically clear-cut differential structures were seen at optical, immunohistochemical, and electron microscopic levels, permitting a clear differential diagnosis. The low-grade ESS expressed hormonal receptors and vimentin, whereas the high-grade ESS showed no hormone receptors, high Ki-67 activity, and occasional cytokeratin-positive cells. Ultrastructurally, no malignant epithelial differentiation was seen in the tumour cells, but cilia were found in both cases. Cytogenetic study of the low-grade ESS showed pseudodiploid karyotype with chromosomes 6 and 20 rearranged. The high-grade ESS showed a complex karyotype with clonal numerical and structural anomalies. The chromosomes involved in the structural rearrangements were 1, 3, 6, 7, 13, 14, 15, 17, 19, and 21. Received: 5 August 1998 / Accepted: 2 November 1998     

Uterine tumour resembling an ovarian sex cord tumour

Endometrial stromal sarcomas account for 0.25% of all uterine malignancies. These tumours were originally divided into low grade and high grade stromal sarcomas, but the recent World Health Organisation classification (2003) recognises low grade stromal sarcoma and undifferentiated endometrial sarcoma. Low grade sarcomas may exhibit other forms of differentiation, including smooth muscle and sex cord differentiation. In the latter form, the tumour contains epithelial-like or sex cord-like elements often with epithelioid appearance, arranged in nests, cords, trabeculae, solid, or tubular structures. If this element predominates, the tumour is considered to be a uterine tumour resembling ovarian sex cord tumour, and may cause diagnostic difficulties. This case report describes the histological and immunohistochemical features of a uterine stromal sarcoma showing exclusively a pattern reminiscent of ovarian sex cord tumour.     

Distinction of endometrial stromal sarcomas from 'hemangiopericytomatous' tumors using a panel of immunohistochemical stains.

Endometrial stromal sarcomas are low-grade malignant tumors that may pose a diagnostic challenge, especially when they are present in an extrauterine site. Owing to the presence of an arborizing vasculature and cells with an undifferentiated appearance, endometrial stromal sarcomas can be confused with several soft-tissue neoplasms. We studied 17 endometrial stromal sarcomas, eight hemangiopericytomas, 14 solitary fibrous tumors, and 16 synovial sarcomas immunohistochemically, detecting the following antigens: CD10, estrogen receptor, progesterone receptor, bcl-2, CD34, smooth muscle antigen, epithelial membrane antigen and cytokeratin (AE1/AE3). Most endometrial stromal sarcomas stained positively for CD10 (16/17), estrogen receptor (17/17), progesterone receptor (15/17), and bcl-2 (17/17). Staining with antismooth muscle antigen was seen in 11 of 17 cases of endometrial stromal sarcoma, with more intense staining seen in areas showing smooth muscle differentiation. Staining with AE1/3 was seen in four of 17 endometrial stromal sarcomas, with two of the positive cases containing epithelioid cells. None of the endometrial stromal sarcomas expressed epithelial membrane antigen or CD34. More than half of the hemangiopericytomas (4/8) and solitary fibrous tumors (9/14) cases demonstrated CD10 expression either focally or in a patchy cytoplasmic and membranous pattern. Hemangiopericytomas, solitary fibrous tumors, and synovial sarcomas did not express estrogen receptor. Four of eight hemangiopericytomas and seven of 14 solitary fibrous tumors also showed patchy progesterone receptor expression. CD34 expression was identified in six of eight hemangiopericytomas and 13 of 14 solitary fibrous tumors, but we did not find expression of CD34 in synovial sarcoma. Differences between endometrial stromal sarcoma and other soft-tissue tumors were detected for all of the immunohistochemical markers (P<0.05), except anti-bcl-2 and AE1/3. Antibodies against CD10 mark a substantial number of hemangiopericytomas and solitary fibrous tumors (albeit not diffusely) and should always be combined with antiestrogen receptor and CD34 when the differential diagnosis includes endometrial stromal sarcoma. Unlike estrogen receptor antibodies, progesterone receptor antibodies show at least focal nuclear staining in most hemangiopericytomas, solitary fibrous tumors and rare synovial sarcomas, and are not useful for this differential diagnosis. All endometrial stromal sarcomas expressed bcl-2, mostly in a diffuse pattern, but this did not distinguish between endometrial stromal sarcoma and mimics. We therefore recommend the use of a small antibody panel comprising anti-CD10, anti-estrogen receptor, and anti-CD34 to distinguish endometrial stromal sarcomas from tumors with a predominant hemangiopericytomatous growth pattern.     

Endometrial stromal tumors: Diagnostic updates and challenges

Endometrial stromal tumors are rare uterine mesenchymal tumors of endometrial stromal origin. They are classified into endometrial stromal nodule, low-grade endometrial stromal sarcoma, high-grade endometrial stromal sarcoma, and undifferentiated uterine sarcoma by the current (2020) WHO classification. Correct diagnosis of endometrial stromal tumors is critical for proper patient management. However, due to infrequent encounters, overlapping morphological features and immunohistochemical profiles, the differential diagnoses among endometrial stromal lesions and their morphologic mimics are often challenging. Partially with our own experience, here we review and summarize the tumor morphology, immunohistochemical phenotype, as well as molecular feature of endometrial stromal tumors and key differential diagnoses, emphasizing the newest developments and their utilization in daily practice.     

子宫内膜间质肉瘤与转移复发瘤的形态特点

目的探讨子宫内膜间质肉瘤(ESS)和转移复发瘤组织形态与免疫组织化学染色特点,及其肿瘤分化特点和鉴别诊断。方法观察15例子宫原发ESS及4例转移复发瘤的组织形态,并用免疫组织化学EnVisonTM二步法检测CD10、平滑肌肌动蛋白(SMA)、雌激素受体(ER)、孕激素受体(PR)、AE1/3及α-抑制素的表达,以10例富于细胞平滑肌瘤作对照。结果15例患者发病年龄22～75岁(平均45岁)。组织学分型:7例经典型,3例平滑肌分化型,2例纤维黏液型,3例分化差型,细胞异型明显。4例复发转移瘤中3例组织形态与原发瘤不同。免疫组织化学染色阳性结果:在14例ESS及4例复发转移瘤中CD1015/18、SMA5/18、ER7/18、PR10/18;AE1/3和α-抑制素仅在腺样分化区阳性。平滑肌瘤对照组CD10为1/10、SMA为10/10,表达差异均有统计学意义(P<0.05)。结论ESS多向分化的特点使其呈现多样的组织形态,且转移复发瘤形态可与原发瘤不同。CD10与SMA联合应用有助于ESS的诊断和鉴别诊断。