Expression of androgen receptors in benign and malignant endometrial stromal neoplasms

Several studies have shown that endometrial stromal neoplasms express estrogen and progesterone receptors (ER, PR). To our knowledge, the presence or absence of androgen receptors (AR) in these rare uterine neoplasms has not been investigated. Tumors (n=20)—3 endometrial stromal nodules, 14 low-grade endometrial stromal sarcomas (ESS, low grade), and 3 high-grade endometrial sarcomas (undifferentiated endometrial sarcoma, UES)—were studied. Immunohistochemical analyses for ER, PR, and AR were performed on formalin-fixed, paraffin-embedded archival material. Positive immunoreactions for ER and PR were observed in 14 (70%) and 17 (85%) cases, respectively. Furthermore, 9 cases (45%) were positive for AR. Among 17 ESS and UES cases, 7 (41%) revealed positivity for AR. Two of three benign stromal nodules were also positive for AR. Moreover, one of the three high-grade sarcomas (undifferentiated endometrial sarcoma) was negative for both ER and PR, but showed positive reaction for AR. In summary, ARs are expressed in 45% of endometrial stromal neoplasms. In addition to determination of ER and PR, the results of immunohistochemical examination of AR in these rare uterine tumors may have some impact on the postoperative management of the patients.     

Inhibin is more specific than calretinin as an immunohistochemical marker for differentiating sarcomatoid granulosa cell tumour of the ovary from other spindle cell neoplasms

AIMS: To describe a case of recurrent sarcomatoid adult granulosa cell tumour (AGCT) of the ovary and to evaluate the usefulness of two ovarian sex cord stromal markers (inhibin and calretinin) in separating sarcomatoid AGCT from true sarcomas. METHODS: A 72 year old woman presented with a recurrent sarcomatoid AGCT in the sigmoid colon mesentery, which histologically mimicked a malignant gastrointestinal stromal tumour (GIST). This index case and 79 sarcomas (32 GISTs, 28 leiomyosarcomas, 15 endometrial stromal sarcomas (ESSs), including one with sex cord-like areas, and four undifferentiated uterine sarcomas) were immunostained using antibodies to inhibin and calretinin. RESULTS: The recurrent sarcomatoid AGCT expressed diffuse, strong cytoplasmic immunoreactivity with inhibin and focal but strong nuclear and cytoplasmic positivity with calretinin. Focal, weak cytoplasmic inhibin expression limited to sex cord-like areas was present in one ESS. None of the other sarcomas expressed inhibin. Focal, strong calretinin immunoreactivity was identified in 11 leiomyosarcomas and one GIST. The case of ESS with sex cord-like areas showed strong immunoreactivity for calretinin limited to the sex cord-like areas. CONCLUSIONS: Inhibin is a useful immunomarker to distinguish sarcomatoid AGCT from other spindle cell neoplasms that may enter into the differential diagnosis. Calretinin appears to be less specific than inhibin.     

CD10 and calretinin staining of endocervical glandular lesions,endocervical stroma and endometrioid adenocarcinomas of the uterine corpus: CD10 positivity is characteristic of,but not specific for,mesonephric lesions and is not specific for endometrial stroma

AIMS: In the female genital tract CD10 has been used to assist in the evaluation of mesenchymal tumours of the uterus and in determining whether endometrial stroma is present. CD10 positivity has also been shown in cervical mesonephric remnants and this antibody has been suggested as a useful immunohistochemical marker of mesonephric lesions in the female genital tract. Calretinin has also been shown to be positive in mesonephric lesions. In this study the specificity of these two antibodies in evaluating cervical and uterine glandular lesions and the value of CD10 in determining whether stroma is endometriotic or not were investigated. METHODS AND RESULTS: Cases of cervical tubo-endometrial metaplasia (TEM) (n = 11), microglandular hyperplasia (MGH) (n = 10), endometriosis (n = 8), mesonephric remnants/hyperplasia (n = 12), endocervical adenocarcinoma, usual type (n = 15), mucinous variant of minimal deviation adenocarcinoma (MDA) (n = 7) and mesonephric adenocarcinoma (n = 3) were stained with antibodies against CD10 and calretinin. Nine cases of endometrial adenocarcinoma of endometrioid type were also stained. In all the cervical cases normal endocervical glands were negative with both antibodies except for one case with strong positive luminal staining with CD10. All cases of TEM, MGH and endometriosis were negative with CD10 and calretinin except for focal staining with CD10 in one case each of MGH (cytoplasmic staining) and endometriosis (luminal staining). Most usual endocervical adenocarcinomas were negative with both antibodies, although one exhibited focal cytoplasmic staining with calretinin and five exhibited limited luminal positivity with CD10. All MDAs were negative with both antibodies. Ten of 12 mesonephric remnants/hyperplasia showed luminal positivity with CD10 and one exhibited cytoplasmic and nuclear staining with calretinin. Two of three mesonephric adenocarcinomas showed luminal positivity with CD10 and nuclear and cytoplasmic positivity with calretinin. Seven of nine endometrial adenocarcinomas were positive with CD10 (four cytoplasmic, two membranous and cytoplasmic, one luminal and cytoplasmic) and three with calretinin (two cytoplasmic, one nuclear and cytoplasmic). Positive staining of endometriotic stroma with CD10 was present in all endometriosis cases but normal cervical stroma was also strongly positive, especially around glands. Endometriotic stroma and cervical stroma were negative with calretinin. CONCLUSIONS: We conclude that most endocervical glandular lesions, including mesonephric remnants/ hyperplasia, are negative with calretinin. However, the focal nuclear and cytoplasmic positivity with calretinin in two of three mesonephric adenocarcinomas suggests that this may be a useful indicator of a mesonephric origin of a cervical adenocarcinoma. Most mesonephric remnants/hyperplasias exhibit luminal positivity with CD10, although this is not invariable and staining is usually focal. Positive luminal staining of a benign endocervical glandular lesion with CD10 may help confirm mesonephric remnants. Although positive staining with CD10 was found in two of three mesonephric adenocarcinomas, the observed immunoreactivity of several conventional cervical adenocarcinomas limits the diagnostic value of CD10 in confirming a mesonephric origin for an adenocarcinoma. Since all cervical MDAs were negative with CD10, positivity with this antibody may be of value in distinguishing mesonephric hyperplasia from MDA, although this distinction rarely necessitates immunohistochemistry. Most endometrial adenocarcinomas of endometrioid type stain with CD10 and thus positivity with this antibody is not specific for a mesonephric origin of an endometrial adenocarcinoma. Positivity of normal cervical stroma limits the value of CD10 staining in confirming a diagnosis of cervical endometriosis.     

Dedifferentiated mixed stromal-smooth muscle tumor of the uterus. Report of a case

So-called dedifferentiation in mesenchymal neoplasms of the uterus is very rare. Among conventional low-grade stromal tumors only three cases of dedifferentiation were reported, whereas in mixed stromal-smooth muscle tumors the dedifferentiation was yet not described. Here we present such a case of low-grade mixed stromal-smooth muscle tumor with dedifferentiation. The tumor occurred in 52-years-old postmenopausal patient. The high-grade component representing a dedifferentiation showed morphology of undifferentiated sarcoma with myxoid change. The low-grade component with morphology of mixed stromal-smooth muscle tumor was limited to a few peripheral areas of the lesion. Immunohistochemically, the low-grade component showed typical positivity for CD10, estrogen receptor, progesterone receptor, and focal reactivity for myoid markers, whereas the dedifferentiated component expressed only vimentin, CD10 and estrogen receptor. This case demonstrates that low-grade mixed stromal-smooth muscle tumor of the uterus can dedifferentiate like a pure stromal tumor. It shows that extensive sampling/histological search may be needed for recognition of a minor component in a dedifferentiated tumor.     

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.     

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.     

Uterine endometrial stromal sarcoma with smooth muscle and glandular differentiation

This report describes a uterine tumour exhibiting areas of both endometrial stromal and smooth muscle differentiation. There was extensive intravascular permeation within the myometrium as well as extrauterine vascular involvement. The endometrial stromal component had a myxoid appearance and the smooth muscle component exhibited the typical features of intravenous leiomyomatosis. An additional feature was the presence of numerous benign endometrial-type glands within the neoplasm. In many areas a "zoning" phenomenon was present, with endometrial glands surrounded by endometrial stroma, which was in turn surrounded by smooth muscle. This unique combination of endometrial glands, endometrial stroma, and smooth muscle has, to the best of our knowledge, not been described previously and adds to the morphological spectrum of mixed endometrial stromal-smooth muscle tumours. This report discusses the differential diagnosis of this lesion, which has been designated a low grade endometrial stromal sarcoma with smooth muscle and glandular differentiation.     

Uterine epithelioid endometrial stromal sarcoma presenting as a "cervical polyp"

Although appearance of conventional uterine endometrial stromal sarcoma is easily recognized on histology, it may uncommonly assume unusual appearances such as uterine tumor resembling ovarian sex-cord tumor, thereby hindering its diagnosis. Recently, its manifestation as an epithelioid neoplasm was described. In this report, we detail yet another instance where this tumor adopted an epithelioid morphology, presenting itself as a polyp extruding from the cervical os in a 41-year-old Chinese woman. Both the polypectomy and subsequent hysterectomy specimens revealed a predominant proliferation of CD10-negative, caldesmon-negative, and CD117-positive epithelioid cells set within a stroma containing vascular proliferation resembling endometrial stromal tumor. Areas of typical low-grade endometrial stromal sarcoma containing spindle cells that were focally positive for CD10 and negative for CD117 were present in close association with the epithelioid areas. The differential diagnoses and possible implication of CD117 positivity are discussed.     

CD10 is useful in demonstrating endometrial stroma at ectopic sites and in confirming a diagnosis of endometriosis

AIMS: Recent studies have shown that CD10 is a useful immunohistochemical marker of normal endometrial stroma and of endometrial stromal neoplasms. The aim of this study was to investigate whether CD10 immunoreactivity is present in ectopic endometrial stroma and whether staining is of value in confirming a diagnosis of endometriosis. METHODS/RESULTS: Twenty five cases of endometriosis were stained with a commercially available antibody against CD10. Endometrial stromal cells were positive in 22 of 25 cases. There was little or no staining of other tissues. CONCLUSIONS: CD10 immunoreactivity is largely maintained in endometrial stromal cells located outside the uterus. Immunohistochemical staining with CD10 may be of value in confirming a diagnosis of endometriosis when there is morphological doubt.     

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.     

Myxoid mesenchymal tumors of uterus: endometrial stromal and smooth muscle tumors, myxoid variant

Four myxoid variant of uterine mesenchymal tumors are reported. One was a low grade stromal sarcoma with infiltrative margins and the others were well circumscribed tumors corresponding to an endometrial stromal nodule and two leiomyomas. They were hypocellular neoplasms composed of stellated cells with an abundant Alcian Blue positive myxoid matrix. The myxoid nature of the neoplasms obscured their cellular nature and made the distinction between smooth muscle and endometrial stromal tumors difficult. Endometrial stromal tumors, showed very focal areas of small basophilic cells, characteristic of endometrial stroma. The diagnosis was based on the presence of a spiral arteriolar network, a CD10 positivity as well as the absence of h-caldesmon and desmin expression. The two myxoid leiomyomas showed more spindle cells and a desmin expression while h-caldesmon was negative and CD10 focally positive in both cases. Myxoid variant of endometrial stromal tumors does not necessarily exhibit the typical morphology of endometrial stroma. They may demonstrate morphological features of smooth muscle tumors in the uterus. Also, myxoid changes in uterin smooth muscle tumors may modify the classical immunoreactivity of smooth muscle markers in these tumors and make it difficult to distinguish between benign and malignant neoplasms. An immunohistochemical panel of antibodies including CD10, h-caldesmon and desmin may help in establishing the correct diagnosis.     

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.     

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.     

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 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     

Low-grade endometrial stromal sarcoma with sex cord-like differentiation metastatic to the thoracic spines

We report a case of monostotic low-grade stromal sarcoma (ESS) with sex cord-like elements metastatic to the thoracic spines, which to the best of our knowledge has not previously been documented. A 48-year-old female who had undergone total abdominal hysterectomy for low-grade endometrial stromal sarcoma 7 years previously presented with insidious onset of severe back pain of 2 months' duration. Magnetic resonance image (MRI) showed involvement of the eleventh and twelfth thoracic vertebral bodies. Decompression at the level of T10-12 was performed. Histologically, the laminae of thoracic vertebrae 11 and 12 were replaced by sheets of ovoid cells with plump nuclei intermixed with anastomosing trabeculae, cords and small nests, reminiscent of a sex-cord stromal tumor pattern. The tumor cells showed diffuse nuclear immunostaining for estrogen receptors (ER) and progesterone receptors (PR), as well as membranous immunostaining for CD10. The immunostaining for smooth muscle actin was focal and sparse. These findings confirmed the diagnosis of metastatic low-grade ESS with sex cord-like differentiation. Low-grade ESS with sex cord-like differentiation is an uncommon tumor which rarely metastasizes to the bone, and use of a panel of ER, PR, CD10, actin, cytokeratin and inhibin immunostains is essential to establish the diagnosis.     

Pulmonary metastases of uterine endometrial stromal sarcoma: diffuse micronodular and ground glass opacities: a case report

Pulmonary metastases of uterine endometrial stromal sarcoma (ESS) are uncommon. The patterns of uterine ESS metastasis to the lung are multiple pulmonary nodules, single nodule, or cystic lesions. Pulmonary intraalveolar micronodular metastases of uterine ESS are unusual and have not been reported. We experienced a case of metastatic uterine ESS presenting as pulmonary diffuse micronodules with ground glass opacities on chest computed tomography of a 37-yr-old woman who previously underwent hysterectomy due to low grade ESS of the uterus four years ago. The histologic findings of video assisted thoracotomy biopsy showed numerous intraalveolar polypoid micronodules protruding from the alveolar septums. All tumor nodules were composed of short spindle cells arranged in ill-defined whorls, and nuclear feature and sparse cytoplasm were seen in uterine ESS. Immunohistochemically, these cells showed strong nuclear staining for estrogen receptor and progesterone receptor, and diffuse cytoplasmic staining for CD10.     

Nucleolar organizer regions in uterine sarcomas

Summary Nucleolar organizer regions demonstrable by silver staining technique (AgNORs) are loops of nucleolar DNA transcribing to ribosomal RNA. This report quantifies AgNORs in normal endometrium and myometrium, and in leiomyomas and homologous sarcomas of the uterus. The mean AgNOR number in leiomyosarcomas was significantly higher than that in normal myometrium and that in leiomyomas, whereas no significant difference was observed between normal myometrium and leiomyomas. The mean AgNOR count in low-grade endometrial stromal sarcomas was significantly higher than that in normal endometrial stroma, and significantly lower than that in the high-grade variant of the same tumour. The epithelial component of malignant mixed müllerian tumours exhibited a significantly higher mean AgNOR number than normal endometrial epithelium, and the stromal component of these tumours showed a significantly higher mean AgNOR count than normal endometrial stroma and normal myometrium, respectively. The AgNOR count was significantly correlated with the mitotic rate in leiomyosarcomas, in high-grade endometrial stromal sarcomas, and in the epithelial and mesenchymal portions of mixed müllerian tumours, whereas no statistically significant correlation was observed in low-grade endometrial stromal sarcomas. Increased AgNOR counts have been reported for some kinds of malignant tumours in various organs, compared with normal tissues and benign tumours. This study demonstrates a similar increase when homologous uterine sarcomas are compared with histogenetically related normal and neoplastic tissues. AgNOR counting might be a useful adjunct in the classification and grading of uterine tumours.     

Immunohistochemical study of high-grade endometrial stromal sarcoma. An autopsy report in comparison with carcinosarcoma, leiomyosarcoma and normal endometrium.

An autopsy case of high-grade endometrial stromal sarcoma (ESS) is reported. Immunohistochemical study of the ESS was done in comparison with carcinosarcoma (CS), leiomyosarcoma (LMS) and normal endometrium in the uterus in order to trace the origin of ESS, which is a point of some controversy. Co-expression of keratin and vimentin and/or desmin positivity in several elements of CS and LMS, and glandular or stromal tissues in normal endometrium made it difficult immunohistochemically to be certain of the origin of ESS.