CD10 is helpful in detecting occult or inconspicuous endometrial stromal cells in cases of presumptive endometriosis

Cutaneous endosalpingiosis arising from C-section scar: A case report with review of literature

Endosalpingiosis is a pathologic phenomenon in which non-neoplastic fallopian tube epithelium implants in ectopic locations. It is an uncommon and poorly understood condition, with most cases occurring within the abdominopelvic cavity. Cutaneous presentations of endosalpingiosis are even more rare, with only six cases described in international literature to-date. This report describes an additional case of cutaneous endosalpingiosis. The lesion arose within the scar tissue of a Pfannenstiel incision from 4 years prior in a 24-year old, previously healthy African American female. Punch biopsy of the lesion revealed a cystic mass lined by PAX8⁺ ciliated columnar cells and a surrounding fibrotic stroma with focal CD10-positivity, consistent with a histopathologic diagnosis of endosalpingiosis. In addition, this report provides a comprehensive review of the other documented cases of cutaneous endosalpingiosis, as well as the proposed pathogenesis, histopathologic and clinical features, and potential treatment avenues for this unique clinical entity.

Histotyping and grading of endometriosis and its association with clinico-pathological parameters

Current clinical staging/grading schemes of endometriosis show poor correlation with clinical symptoms and histopathological confirmation is only in half of the clinically suspected endometriosis. In this study, done over an 8-year period, several histological features were analysed including an attempt to grade the severity of endometriosis histologically based on the number of foci per low power field. The components in each focus, the phasing of the glands and stroma, the type of glands (endometrial type or undifferentiated type), and stromal features were all analysed. This study attempts to histologically grade endometriosis while relating it to the clinical manifestations and anatomical location. Eighty cases of endometriosis were included. Most common clinical presentation was cyclical pain (n = 62) and the most common anatomical location was adnexa (n = 50). Histologically, severe endometriosis (>3 foci) was seen in 37 cases. The components were mixed in 68 cases. Well-differentiated glandular pattern was typical (n = 54), while 6 cases had undifferentiated. Proliferative phase was seen in 38 cases. Fibrosis and inflammation were present in 29 and 42 cases, respectively. Significant vascular proliferation and plasma cell infiltrate was noted (n = 35). The severe grade was significantly associated with fibrosis (p = 0.03) and inflammation (p = 0.014). Endometriotic foci, unlike eutopic endometrium, shows significant plasma cell infiltrate and vascular proliferation.IMPACT STATEMENTWhat is already known on this subject? Endometriosis, a chronic inflammatory condition in reproductive age group women. The currently used clinical staging and grading systems show poor correlation with patient symptoms and treatment outcomes. Endometriosis with classical histopathological features pose no diagnostic difficulty, however, there is poor concordance with histopathology. Atypical endometriosis is proposed as potential precursor for endometriosis related neoplasms, however, it remains as a controversial entity.What do the results of this study add? The study identifies the uncommon histological patterns which may be encountered in biopsy samples from clinically identified endometriotic lesions. The recognition of these patterns will reduce clinico-pathological discrepancies. In keeping with the other grading systems, attempts at histological grading did not show any correlation with location or patient symptoms. Atypical features were seen only in two cases and was likely to be reactive in nature.What are the implications of these findings for clinical practice and/or further research? Undifferentiated glandular pattern is often a under-recognized histological pattern. Histological grading of severity was a novel attempt to correlate with clinical parameters. Significant plasma cell infiltrate and vascular proliferation in endometriotic foci, underscores the quest for novel therapeutic targets. This study suggests that the use of non-invasive diagnostic methods like fibroscan/inflammatory markers to clinically identify severe disease should be investigated further.

Combined expression of HOXA11 and CD10 identifies endometriosis versus normal tissue and tumors

The gold standard for diagnosing endometriosis is by laparoscopic visual demonstration of ectopic endometrial lesions outside the uterus, preferably verified by biopsy and microscopical examination. Molecular markers to facilitate the microscopical diagnosis of endometriosis and for distinguishing endometriosis from other benign and malignant lesions are lacking. Our aim was to test and validate an immunohistochemical antibody panel for improved diagnostic accuracy of endometriosis. Both CD10 and HOXA11 have been implicated in regulation of endometrial homeostasis. Here we have analyzed the expression pattern of these two proteins using immunohistochemistry on human tissues in a tissue microarray format. CD10 and HOXA11 expression in endometriosis lesions were compared to expression patterns in a range of normal tissues and in primary- and metastatic lesions of endometrial-, cervical- and ovarian cancer. HOXA11 and CD10 were expressed in 98% and 91% of endometriosis lesions and the combined double-positive expression profile of both HOXA11 and CD10 was highly sensitive for ectopic endometrial tissue (90%). The specificity and sensitivity for this double-positive signature in endometriosis was significantly different from all investigated tissues, cancers and metastases except normal, eutopic endometrial- and cervical mucosa. The combination of HOXA11 and CD10 expression profiles provides a useful tool to identify ectopic endometrial tissue and for distinguishing endometriosis from various types of gynecological malignancies and metastases.

IFITM1, CD10, SMA, and h-caldesmon as a helpful combination in differential diagnosis between endometrial stromal tumor and cellular leiomyoma

Background

The differential diagnosis of endometrial stromal tumor (EST) and uterine cellular leiomyoma (CL) remains a challenge in clinical practice, especially low grade endometrial stromal sarcoma (ESS) and CL, suggesting the need for novel immunomarkers panels for differential diagnosis. Interferon-induced transmembrane protein 1 (IFITM1) is a novel immunomarker for endometrial stromal cells, h-caldesmon is an immunomarker for smooth muscle cells and has a higher specificity than smooth muscle actin (SMA). So this study aimed to evaluate whether IFITM1, cluster of differentiation 10(CD10), SMA, and h-caldesmon are useful biomarker combinations for the differential diagnosis of EST and CL.

Methods

Tissue microarrays were used to detect IFITM1, CD10, SMA, and h-caldesmon immunohistochemical staining in 30 EST and 33 CL cases.

Results

The expressions of IFITM1 and CD10 were high in EST (86.7 and 63.3%, respectively) but low in CL (18.2 and 21.2%), whereas those of h-caldesmon and SMA were high in CL (87.9 and 100%) and low in EST (6.9 and 40%). In diagnosing EST, IFITM1 shows better sensitivity and specificity (86.7 and 81.8%, respectively) than CD10 (63.3 and 78.8%). The specificity of h-caldesmon in diagnosing CL was significantly higher (93.1%) than that of SMA (60%). When all four antibodies were combined for the differential diagnosis, the area-under-the-curve (AUC) predictive value was 0.995. The best combination for diagnosing EST was IFITM1 (+) or CD10 (+) and h-caldesmon (−) (sensitivity 86.7%, specificity 93.9%).

Conclusion

The best combination for diagnosing CL were h-caldesmon (+) and SMA (+) (sensitivity 87.9%, specificity 100%). IFITM1, CD10, SMA, and h-caldesmon are a good combination for the differential diagnosis of EST and CL.

The Importance of Stromal Endometriosis in Thoracic Endometriosis

Thoracic endometriosis (TE) is a rare type of endometriosis, where endometrial tissue is found in or around the lungs and is frequent among extra-pelvic endometriosis patients. Catamenial pneumothorax (CP) is the most common form of TE and is characterized by recurrent lung collapses around menstruation. In addition to histology, immunohistochemical evaluation of endometrial implants is used more frequently. In this review, we compared immunohistochemical (CPE) with histological (CPH) characterizations of TE/CP and reevaluated arguments in favor of the implantation theory of Sampson. A summary since the first immunohistochemical description in 1998 until 2019 is provided. The emphasis was on classification of endometrial implants into glands, stroma, and both together. The most remarkable finding is the very high percentage of stromal endometriosis of 52.7% (CPE) compared to 10.2% (CPH). Chest pain, dyspnea, right-sided preference, and diaphragmatic endometrial implants showed the highest percentages in both groups. No significant association was found between the recurrence rate and the various appearances of endometriosis. Sometimes in CPE (6.8%) and CPH (30.6%) no endometrial implants were identified underlining the importance of sensitive detection of endometriosis during and after surgery. We suggest that immunohistochemical evaluation should become mandatory and will improve diagnosis and classification of the disease.

IFITM1 is a Novel, Highly Sensitive Marker for Endometriotic Stromal Cells in Ovarian and Extragenital Endometriosis

When the presence of endometriotic lesions are not evident by hematoxylin and eosin staining, CD10 is used to highlight and confirm the presence of endometriotic stroma. However, CD10 is not specific only to the endometrial stroma but is also expressed in many other cells. Recently, interferon-inducible transmembrane protein 1 (IFITM1) was reported as a highly specific immunohistochemical marker of normal endometrial stroma and endometrial stromal neoplasm. In this study, we examined the expression of IFITM1 and CD10 in 18 cases of ovarian endometriosis and 44 cases of extragenital endometriosis. Among the 62 patients, 62 (100.0%) were positive for IFITM1 and 60 (96.8%) for CD10, and CD10 was negative in 2 cases that were positive for IFITM1. Additionally, we found that IFITM1 sensitivity was unaffected by the presence or absence of hormonal therapy. To the best of our knowledge, this represents the first demonstration of IFITM1 as a highly sensitive stromal marker of ovarian and extragenital endometriosis.

Endometriosis-related pathology: a discussion of selected uncommon benign, premalignant and malignant lesions

Endometriosis is an extremely common condition and, in most cases, establishing a histological diagnosis is straightforward, although a variety of benign alterations may result in problems with interpretation. In this review, I discuss selected uncommon variants of endometriosis or benign alterations that may result in diagnostic problems. The topics covered include the contentious issue of so-called atypical endometriosis, stromal endometriosis, polypoid endometriosis, and the association of endometriosis with florid mesothelial hyperplasia. The propensity of endometriosis to undergo neoplastic transformation (especially to endometrioid and clear cell carcinoma) is well known. Selected issues relating to the various neoplasms that can arise in endometriosis are discussed, with a particular concentration on unusual variants of endometrioid carcinoma that result in a disproportionately high number of issues in referral practice. The propensity of ovarian endometrioid carcinomas to show an unexpected ('aberrant') immunophenotype with positive staining with 'intestinal' markers and negative staining with Mullerian markers is also discussed. Uncommon tumour types that may arise in endometriosis, namely seromucinous neoplasms, mesonephric-like carcinomas, and somatically derived yolk sac tumours, are also covered.

Reassessment of prevalence of tubal endometriosis, and its associated clinicopathologic features and risk factors in premenopausal women received salpingectomy

Introduction

To reassess the prevalence of fallopian tube endometriosis (EM), and its associated clinicopathologic characteristics and risk factors.

Methods

Cross-sectional study was conducted from June 2016 to August 2017. Unpregnant premenopausal women who underwent unilateral or bilateral salpingectomy due to gynecologic diseases were recruited. Patient clinical data and fallopian tube specimens were collected. Hematoxylin-eosin (H&E) staining and CD10 immunohistochemistry were used to diagnose tubal EM.

Results

Tubal EM prevalence was 14.48% (161/1112, 95% confidence interval [CI] 12.41%–16.55%). Prevalence of tubal EM in patients with EM was 37.37% (95%CI 30.58%–44.17%) which is higher in patients without EM (9.52%, 95%CI 7.61%–11.42%) and even higher in those with multi-organ EM (43.94%, 95%CI 35.36%–52.52%). At unilateral or bilateral salpingectomy, tubal EM was more likely located in the left fallopian tube (52.17%) than the right one (40.37%) and presence of hydrosalpinx/ hematosalpinx increased in women with tubal EM than without tubal EM (43.47% versus 23.79%). With increasing severity of pelvic EM (r = 0.26, P<10⁻⁴) and adhesion (r = 0.25, P<10⁻⁴), the tubal EM prevalence also increased. Pathological examination found that tubal EM was more likely located in the mucosa of the proximal tube with significantly more surrounding inflammation and fibrotic lesions than the serosa/sub-serosa in the distal tube (r = 0.90, P<10⁻⁴). Multivariate analysis showed that abnormal uterine bleeding (AUB) (AOR = 3.10), previous EM surgery (AOR = 4.22) and tubal ligation (AOR = 2.33) were risk factors for tubal EM.

Conclusions

These data provide clinicians with important information that the prevalence of tubal EM among premenopausal unpregnant patients was higher than previous investigators, especially higher among women with EM diseases. Identifying its clinicopathologic characteristics and predictors may facilitate clinical decision making.

Comparison of enhanced laparoscopic imaging techniques in endometriosis surgery: a diagnostic accuracy study

Background

For surgical endometriosis, treatment key is to properly identify the peritoneal lesions. The aim of this clinical study was to investigate if advanced imaging improves the detection rate by comparing narrow-band imaging (NBI), near-infrared imaging with indocyanine green (NIR-ICG), or three-dimensional white-light imaging (3D), to conventional two-dimensional white-light imaging (2D) for the detection of peritoneal endometriotic lesions.

Methods

This study was a prospective, single-center, randomized within-subject, clinical trial. The trial was conducted at Amsterdam UMC—Location VUmc, a tertiary referral hospital for endometriosis. 20 patients with ASRM stage III–IV endometriosis, scheduled for elective laparoscopic treatment of their endometriosis, were included. During laparoscopy, the pelvic region was systematically inspected with conventional 2D white-light imaging followed by inspection with NBI, NIR-ICG, and 3D imaging in a randomized order. Suspected endometriotic lesions and control biopsies of presumably healthy peritoneum were taken for histological examination. The pathologist was blinded for the method of laparoscopic detection. Sensitivity and specificity rates of the enhanced imaging techniques were analyzed. McNemar’s test was used to compare sensitivity to 2D white-light imaging and Method of Tango to assess non-inferiority of specificity.

Results

In total, 180 biopsies were taken (117 biopsies from lesions suspected for endometriosis; 63 control biopsies). 3D showed a significantly improved sensitivity rate (83.5% vs. 75.8%, p = 0.016) and a non-inferior specificity rate (82.4% vs. 84.7%, p = 0.009) when compared to 2D white-light imaging. The single use of NBI or NIR-ICG showed no improvement in the detection of endometriosis. Combining the results of 3D and NBI resulted in a sensitivity rate of 91.2% (p < 0.001).

Conclusion

Enhanced laparoscopic imaging with 3D white light, combined with NBI, improves the detection rate of peritoneal endometriosis when compared to conventional 2D white-light imaging. The use of these imaging techniques enables a more complete laparoscopic resection of endometriosis.

IFITM1 is a Novel, Highly Sensitive Marker for Endometriotic Stromal Cells in Ovarian and Extragenital Endometriosis

When the presence of endometriotic lesions are not evident by hematoxylin and eosin staining, CD10 is used to highlight and confirm the presence of endometriotic stroma. However, CD10 is not specific only to the endometrial stroma but is also expressed in many other cells. Recently, interferon-inducible transmembrane protein 1 (IFITM1) was reported as a highly specific immunohistochemical marker of normal endometrial stroma and endometrial stromal neoplasm. In this study, we examined the expression of IFITM1 and CD10 in 18 cases of ovarian endometriosis and 44 cases of extragenital endometriosis. Among the 62 patients, 62 (100.0%) were positive for IFITM1 and 60 (96.8%) for CD10, and CD10 was negative in 2 cases that were positive for IFITM1. Additionally, we found that IFITM1 sensitivity was unaffected by the presence or absence of hormonal therapy. To the best of our knowledge, this represents the first demonstration of IFITM1 as a highly sensitive stromal marker of ovarian and extragenital endometriosis.

Effects of pelvic endometriosis and adenomyosis on ciliary beat frequency and muscular contractions in the human fallopian tube

BACKGROUND

Pelvic endometriosis (EM) and adenomyosis (AM) have different effects on the fallopian tube. This study aimed to assess the transport capability of the fallopian tube in women with pelvic EM or AM.

METHODS

Twenty women with uterine leiomyoma (control group), 20 with adenomyosis without pelvic EM (AM group) and 35 with pelvic EM without AM (EM group) were included. EM cases were further divided into the tubal EM and non-tubal EM subgroups. Ciliary beat frequency (CBF), percentage of ciliated cells, and smooth muscle contraction were measured.

RESULTS

CBFs of the ampulla in EM cases were significantly lower than those of control and AM cases; CBFs of the ampulla and isthmus in tubal EM cases were significantly lower than those of the control group and non-tubal EM subgroup. In both the ampulla and isthmus segment, percentages of ciliated cells in EM patients were significantly lower than those of AM and control patients; the tubal EM subgroup showed significantly lower values than the control group and non-tubal EM subgroup. Amplitude-to-weight ratios of longitudinal muscular contractility in EM cases were significantly lower than control values; tubal EM cases showed significantly lower values than controls and the non-tubal EM subgroup. Contraction frequencies in EM cases were significantly lower than those of control and AM cases, in both longitudinal and circular muscles; tubal EM cases showed significantly lower values than controls and the non-tubal EM subgroup.

CONCLUSION

EM with tubal EM damaged transport function of the fallopian tube, to varying degrees, whereas tubal function in EM without tubal EM and in AM is not altered.

Composition of the Stroma in the Human Endometrium and Endometriosis

To analyze whether the endometrial and endometriotic microenvironment is involved in the pathogenesis of endometriosis, we characterized the stromal composition. We used CD90 for fibroblasts, α-smooth muscle actin for myofibroblasts as well as CD10 and CD140b for mesenchymal stromal cells. Quantification of eutopic endometrial stroma of cases without endometriosis showed a high percentage of stromal cells positive for CD140b (80.7%) and CD10 (67.4%), a moderate number of CD90-positive cells (57.9%), and very few α-smooth muscle actin-positive cells (8.5%). These values are highly similar to cases with endometriosis showing only minor changes: CD140b (76.7%), CD10 (63%), CD90 (53.9%), and α-smooth muscle actin (6.9%). There are no significant differences in the composition of CD140b- and CD10-positive stromal cells between the eutopic endometrial stroma and the 3 different endometriotic entities (ovarian, peritoneal, and deep infiltrating endometriosis), except for a significant difference between CD10-positive stromal cells in peritoneal lesions compared to ovarian lesions. However, the percentage of CD90-positive stromal cells was reduced in the 3 different endometriotic entities compared to the endometrium, especially significant in the ovarian lesions. In contrast, the percentage of α-smooth muscle actin-positive cells in the ovary was moderately increased. Taken together, the marker signature of eutopic endometrial and endometriotic stromal cells resembles mostly mesenchymal stromal cells. Our results show clearly that the proportion of the different stromal cell types in the endometrium with or without endometriosis does not differ significantly, thus suggesting that the stromal eutopic endometrial microenvironment does not contribute to the pathogenesis of endometriosis.

Morphologic Features Suggestive of Endometriosis in Nondiagnostic Peritoneal Biopsies

Endometriosis is a common disorder that causes significant morbidity from dysmenorrhea, pelvic pain, and subfertility. Establishment of a definitive diagnosis has important therapeutic implications; however, only approximately 50% of biopsies of laparoscopically suspicious areas provide a diagnosis of endometriosis. Histologic criteria for diagnosis require the presence of endometrial glands or endometrial-type stroma. We hypothesize that other frequently present, but nondiagnostic, histologic features of endometriosis suggest its presence in patients with nondiagnostic peritoneal biopsies. We performed a retrospective clinicopathologic study of morphologic and immunohistochemical features that may improve the histologic diagnosis of endometriosis on laparoscopic peritoneal biopsies. We compared diagnostic (n=88) and nondiagnostic (n=54) peritoneal biopsies from pathologically confirmed endometriosis cases with negative peritoneal biopsies (n=84) from early-stage gynecologic cancer cases. Statistical analysis utilized the Fisher exact test. Multiple morphologic features were significantly increased in nondiagnostic biopsies from patients with endometriosis in comparison with those from negative controls, including foamy macrophages (P=0.0001) and submesothelial stromal clusters (SSCs) (P=0.0008). SSCs ranged from subtle aggregates of spindle cells to nodules of whorled spindle cells with small vessels and extravasated red blood cells resembling stromal endometriosis. Immunohistochemical studies confirmed that ER and CD10-positive SSCs were present in a greater proportion of both nondiagnostic and diagnostic peritoneal biopsies and at a greater number of lesions per biopsy. The overall histologic detection rate of peritoneal biopsies for endometriosis was 62.0%, and inclusion of SSCs with or without foamy macrophages in the diagnostic criteria appreciably increased this rate to between 72.5% and 76.8%. We describe SSCs, which appear to be an early or less developed form of stromal endometriosis, and, when included in the diagnostic criteria, improve the histologic detection rate of endometriosis in peritoneal biopsies.

Histological evaluation of ureteral involvement in women with deep infiltrating endometriosis: analysis of a large series

STUDY QUESTION

In women with deeply infiltrating endometriosis (DIE) what is the prevalence of involvement of endometriotic tissue and fibrosis in ureteral endometriosis (UE), as assessed by histological staining?

SUMMARY ANSWER

In women with DIE, ureteral involvement is more often due to endometriotic tissue rather than fibrosis.

WHAT IS KNOWN ALREADY

In the current literature, histological evaluation of ureteral endometriosis is mainly based on the degree of wall infiltration by endometriosis instead of the tissue composition. A few studies reported ill-defined and contradictory histological data on the tissue composition of UE.

STUDY DESIGN, SIZE, DURATION

Retrospective observational study based on clinical records of women affected by DIE, laparoscopically treated for UE at a tertiary referral center, between January 2010 and March 2013. All cases of ureteral nodule excision or ureterectomy with histological examination of the specimens were included. Exclusion criteria were other identified causes of hydroureteronephrosis, medical therapy for a period of at least 3 months before surgery and previous surgery for DIE.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 77 patients were included in the study and among them seven (9%) presented with bilateral ureteral involvement, giving a total of 84 cases of UE available for analysis. All patients had stage IV endometriosis. According, respectively, to the presence of endometrial glands and/or stroma cells or of fibrotic tissue only, the endometriotic UE and fibrotic UE groups were compared with regard to hydroureteronephrosis at pre-operative urinary tract computerized tomography scan, type of surgical procedure performed to treat UE (nodule removal or ureterectomy), association with other locations of the disease and post-operative complications (ureteral fistula or stenosis).

MAIN RESULTS AND THE ROLE OF CHANCE

For the 84 cases of UE, 65 (77%) and 19 (23%), respectively, showed endometriotic tissue and fibrotic tissue only. Presence of hydroureteronephrosis and endometriotic pattern of UE showed a significant association [endometriotic UE 44/65 (68%) versus fibrotic UE 8/19 (42%); P = 0.04]. Fibrotic pattern of UE and presence of concomitant recto-vaginal endometriosis showed a significant association [endometriotic group: 29/65 (45%) versus fibrotic group 18/19 (95%); P < 0.001].

LIMITATIONS, REASONS FOR CAUTION

The retrospective and monocentric (tertiary referral center) study design.

WIDER IMPLICATIONS OF THE FINDINGS

Besides the distinction between extrinsic and intrinsic UE based on the degree of wall infiltration by endometriosis, a new classification according to the histological pattern of UE could be useful for clinicians, both in the diagnostic and therapeutic fields.

STUDY FUNDING/COMPETING INTERESTS

None.

Temporal changes in neutral endopeptidase/CD10 immunoexpression in the cyclic and early pregnant canine endometrium

CD10 is a multifunctional transmembrane neutral endopeptidase (NEP) that is considered to be a reliable marker of ectopic human endometrial stroma. Available information on NEP/CD10 protein expression in animal endometria is scarce. This study focused on the immunolocalization of NEP/CD10 in the canine uterus and on its temporal changes during the estrous cycle and early pregnancy (Days 11 to 23 post-LH surge) in healthy females. NEP/CD10 expression was found in the canine endometrial stroma in all stages of the estrous cycle, showing cyclic differences both in intensity and in distribution pattern. A small population of negative stromal cells in subsurface position was also observed. This population shared some morphological characteristics with the human predecidual cells, which became positive in progesterone-associated stages of the cycle. In addition, positive immunolabeling was also observed in canine myometrial stroma. In early pregnancy, the basal glandular epithelia and the syncytium cords remained negative to this marker contrasting with the trophoblast and the lacunar epithelium. A weak to moderate intensity of immunolabeling was observed in the decidual cells, whereas stromal immunolabeling was more intense at the delimitation of the syncytium cords. In conclusion, CD10 is consistently expressed in the canine endometrial stroma and myometrium but not in the endometrial epithelia. The characteristic pattern seen in early pregnancy also suggests a role for this molecule in the process of embryo invasion at implantation.

In vitro model of stromal and epithelial immortalized endometriotic cells

Endometriosis is a relatively common chronic gynecologic disorder that usually presents with chronic pelvic pain or infertility. It results from implantation of endometrial tissue outside the uterine cavity. Despite its frequency and its impact on quality of life, the understanding of pathogenesis of endometriosis remains incomplete and its treatment remains controversial. In this work, we established a suitable in vitro model system of immortalized human endometriotic cell line taking advantage of the human telomerase reverse transcriptase. The results demonstrate that these cells retain the natural characteristics of endometrial cells in term of phenotype and of functional expression of estrogen and progesterone receptors, without chromosomal abnormalities. In conclusion, these cells are potentially useful as an experimental model to investigate endometriosis biology.

Undifferentiated Endometrial Sarcoma of the Ovary: A Case Report with Review of Recent Literature and Discussion of Lacking Specificity of CD10 Immunoreactivity

Undifferentiated endometrial sarcomas (UESs) of the ovary are very rare tumors. This paper presents a case of a 56-year-old patient with a history of hysterectomy and bilateral salpingectomy seven years ago for uterine leiomyomata. Intraoperatively, a tumor originating from the left ovary, adherent to the sigmoid colon, with infiltration of the small intestine and the vaginal apex was found. Histologically, the tumor was composed of pleomorphic round and oval to spindled cells with polymorphous vesicular nuclei with coarse chromatin and large nucleoli. Mitotic activity was brisk. There were large necrotic areas. Adjacent to the tumor tissue endometrium-like glands surrounded by fibrous stroma with macrophages corresponding to ovarian endometriosis were noted. Tumor cells showed diffuse strong immunoreactivity for vimentin and patchy strong staining for CD10; no reactivities were found for AE1/AE3, desmin, S-100, LCA, CD20, c-kit, and CD31. The patient died of her neoplastic disease four months postoperatively. CD10 is frequently expressed in different gynecopathological as well as other lesions, and, thus, nonspecific without relevance to the classification of this case. Morphological features, extensive sampling, and appropriate immunohistochemistry including markers for cytokeratins and myogenic differentiation are mandatory to arrive at the correct diagnosis.

The use of Fluorescence Resonance Energy Transfer (FRET) peptidesfor measurement of clinically important proteolytic enzymes

Proteolytic enzymes have a fundamental role in many biological processes and are associated with multiple pathological conditions. Therefore, targeting these enzymes may be important for a better understanding of their function and development of therapeutic inhibitors. Fluorescence Resonance Energy Transfer (FRET) peptides are convenient tools for the study of peptidases specificity as they allow monitoring of the reaction on a continuous basis, providing a rapid method for the determination of enzymatic activity. Hydrolysis of a peptide bond between the donor/acceptor pair generates fluorescence that permits the measurement of the activity of nanomolar concentrations of the enzyme. The assays can be performed directly in a cuvette of the fluorimeter or adapted for determinations in a 96-well fluorescence plate reader. The synthesis of FRET peptides containing ortho-aminobenzoic acid (Abz) as fluorescent group and 2, 4-dinitrophenyl (Dnp) or N-(2, 4-dinitrophenyl)ethylenediamine (EDDnp) as quencher was optimized by our group and became an important line of research at the Department of Biophysics of the Federal University of São Paulo. Recently, Abz/Dnp FRET peptide libraries were developed allowing high-throughput screening of peptidases substrate specificity. This review presents the consolidation of our research activities undertaken between 1993 and 2008 on the synthesis of peptides and study of peptidases specificities.

Pelvic endometriosis is rarely associated with ovarian borderline tumours, cytologic and architectural atypia: a clinicopathologic study

Endometriotic foci, especially ovarian ones, with epithelial cytologic atypia may be precursors of cancer. This study presents an overview of the atypical cytological and histopathological findings associated with endometriosis. Six cases of endometriosis, with atypical histological and cytological changes, were obtained from the archives of the Department of Pathology at Cleveland Clinic Foundation between year 2000 and 2003. The size of the base from which these cases were drawn was 2000 cases of endometriosis. The age range of the patients was from 29 to 52 years. The clinical presentations included infertility (three cases), pelvic pain (three cases), adenexal and pelvic masses (four cases). Stage IV endometriosis with extensive pelvic involvement was found in two patients. Intraoperatively, the endometriotic lesions involved the ovaries (all cases); Cul de sac (four cases); urinary bladder (two cases); sigmoid colon, hemidiaphragms, and uterine vessels (one case each). The endometriotic lesions were associated with uterine leiomyomas (two patients) and adenocarcinoma of the vagina (one patient). Histologically, in addition to endometrial type glands and stroma, usually found in endometriosis, we observed both cytologic and pattern atypism involving the epithelium in all cases. The features of cytologic atypia included nuclear stratification, hyperchromatism, and pleomorphism. The features of pattern atypia were complex glandular pattern, papillary formations and psammoma bodies. In two cases, these features were sufficient for diagnosis of borderline Mullerian seromucinous tumours. One patient had recurred with metastatic adenocarcinoma of the vault. She died later from disseminated metastatic disease. There is a rare association between pelvic endometriosis and borderline ovarian tumours (three cases), cytologic and pattern atypia (two cases); mesothelial hyperplasia, endosalpingiosis (two cases), and metastasis (one case). Cytologic and pattern atypia can develop in the endometriotic foci and therefore, these lesions should be thoroughly scrutinized for presence of these changes. Our findings recommend surgical excision of these foci rather than their simple cauterization.

CD10 Expression in Pure Stromal and Sex Cord-Stromal Tumors of the Ovary

CD10 has been recently advocated as a good immunohistochemical marker for endometrial stromal tumors. Metastatic endometrial stromal tumors to the ovary and primary endometrioid stromal sarcomas may show overlapping histological features with pure stromal and sex cord-stromal tumors (SCSTs). We investigated CD10 expression in a large series of pure stromal and SCSTs of the ovary to ascertain whether CD10 may aid in this differential diagnosis. Archival material from 11 fibromas, 10 thecomas, 10 sclerosing stromal tumors (SSTs), 10 adult granulosa cell tumors (AGCTs), 4 luteinized AGCTs, 9 juvenile granulosa cell tumors (JGCTs), 9 Sertoli cell tumors, 9 Sertoli-Leydig cell tumors, 11 sex cord tumors with annular tubules, 10 steroid cell tumors (StCTs), and 8 fibrosarcomas of the ovary were immunostained for CD10. The percentage of cells stained (<5%, 5%-39%, 40%-75%, and >75%) and intensity of staining (1+, 2+, 3+) were evaluated. CD10 was expressed in 7 of 10 thecomas (4 with 5%-75% and mostly 1+), 9 of 10 SSTs (7 with 5%-39% + cells, mostly 1+), 9 of 10 AGCTs (<5%-39%, four 1+, five 2+), 1 of 4 luteinized AGCTs (<5% and 1+), 8 of 9 JGCTs (mostly <5% to 39% and +1), 4 of 9 Sertoli cell tumors (either focal or >75% with variable intensity), 4 of 9 Sertoli-Leydig cell tumors (mostly <10% with variable staining), with the Leydig cells being positive in only 1 tumor (1+ and <5%), and 7 of 10 StCTs (4 tumors with more than 75% + cells, from 1+ to 3+). All fibromas, all but 1 fibrosarcoma (<5% and 1+), and all sex cord tumors with annular tubules were CD10 negative. CD10 expression was frequently seen in StCTs, SSTs, and thecomas of the ovary, although the latter 2 categories usually showed only faint immunoreactivity. In conclusion the frequency and intensity of CD10 immunoreactivity in pure stromal and sex cord-stromal ovarian tumors are low and contrast with the typical strong and diffuse immunostaining seen in endometrial stromal tumors; however, faint CD10 positivity is consistent with the diagnosis of ovarian SCST. Steroid cell tumors are often positive for CD10, but these tumors do not pose problems in differential diagnosis with endometrial stromal tumors. CD10 may play a useful role in aiding the differential between endometrial stromal tumors in the ovary and SCST and stromal tumors.

The pathology of endometriosis: a survey of the many faces of a common disease emphasizing diagnostic pitfalls and unusual and newly appreciated aspects

Although the histologic diagnosis of endometriosis is usually straightforward, many diagnostic problems can arise as a result of alterations or absence of its glandular or stromal components. The diagnostic difficulty in such cases can be compounded by tissue that is limited to a small biopsy specimen. The appearance of the glandular component can be altered by hormonal and metaplastic changes, as well as cytologic atypia and hyperplasia. Although the last 2 findings are often referred to collectively as "atypical endometriosis," they should be separately recognized as their premalignant potential likely differs. In some cases, the endometriotic glands are sparse or even absent (stromal endometriosis). The stromal component can be obscured or effaced by infiltrates of foamy and pigmented histiocytes, fibrosis, elastosis, smooth muscle metaplasia, myxoid change, and decidual change. Occasional findings in endometriosis that may raise concern for a neoplasm include necrotic pseudoxanthomatous nodules, polypoid growth (polypoid endometriosis), bulky disease, and venous, lymphatic, or perineural invasion. Inflammatory and reactive changes within, adjacent to, or at a distance from foci of endometriosis can complicate the histologic findings and include infection within endometriotic cysts, pseudoxanthomatous salpingitis, florid mesothelial hyperplasia, peritoneal inclusion cysts, and Liesegang rings. The histologic diagnosis of endometriosis can also be challenging when it involves an unusual or unexpected site. Five such site-specific problematic areas considered are endometriosis on or near the ovarian surface, superficial cervical endometriosis, vaginal endometriosis, tubal endometriosis, and intestinal endometriosis, including the important distinction of an endometrioid carcinoma arising from colonic endometriosis from a primary colonic adenocarcinoma. Finally, endometriotic foci can occasionally be intimately admixed with another process, such as peritoneal leiomyomatosis or gliomatosis, resulting in a potentially confusing histologic appearance.

Neprilysin carboxydipeptidase specificity studies and improvement in its detection with fluorescence energy transfer peptides

We examined the substrate specificity of the carboxydipeptidase activity of neprilysin (NEP) using fluorescence resonance energy transfer (FRET) peptides containing ortho-aminobenzoyl (Abz) and 2,4-dinitrophenyl (Dnp) as a donor/acceptor pair. Two peptide series with general sequences Abz-RXFK(Dnp)-OH and Abz-XRFK(Dnp)-OH (X denotes the position of the altered amino acid) were synthesized to study P1 (cleavage at the X-F bond) and P2 (cleavage at R-F bond) specificity, respectively. In these peptides a Phe residue was fixed in P1' to fulfill the well-known NEP S1' site requirement for a hydrophobic amino acid. In addition, we explored NEP capability to hydrolyze bradykinin (RPPGFSPFR) and its fluorescent derivative Abz-RPPGFSPFRQ-EDDnp (EDDnp=2,4-dinitrophenyl ethylenediamine). The enzyme acts upon bradykinin mainly as a carboxydipeptidase, preferentially cleaving Pro-Phe over the Gly-Phe bond in a 9:1 ratio, whereas Abz-RPPGFSPFRQ-EDDnp was hydrolyzed at the same bonds but at an inverted proportion of 1:9. The results show very efficient interaction of the substrates' C-terminal free carboxyl group with site S2' of NEP, confirming the enzyme's preference to act as carboxydipeptidase at substrates with a free carboxyl-terminus. Using data gathered from our study, we developed sensitive and selective NEP substrates that permit continuous measurement of the enzyme activity, even in crude tissue extracts.

Immunohistochemical analysis of an ectopic endometriosis in the uterine round ligament

A rare case of the inguinal endometriosis was reported with immunohistochemical analysis. A 28-year-old woman had a thumb-sized tumor in the right groin for two years with a gradual increase in size and pain. An operation revealed an elastic hard tumor with an unclear margin and adhesion to the uterine round ligament. The histology showed irregular proliferation of the endometrial glands and stroma. The glandular epithelium stained weakly positive against CD125 antibody and the stromal matrix stained strongly positive against CD10 antibody. The nucleus in both the epithelial and stromal cells stained strongly positive against progesterone and estrogen receptor antibodies, and the cytoplasm in both types of cells stained moderately positive against COX-2 (cyclooxygenase-2) antibody. In conclusion, the combination of estrogen or progesterone receptor antibody for the nucleus and CD10 or COX-2 antibody for the cytoplasm could enhance the accuracy of diagnosis for ectopic endometriosis.

Sciatic endometriosis diagnosed by computerized tomography–guided biopsy and CD10 immunohistochemical staining

OBJECTIVE

To report a case of sciatic endometriosis diagnosed by computerized tomography (CT)-guided biopsy in combination with CD10 immunohistochemical staining.

DESIGN

Case report.

SETTING

University hospital.

PATIENT(S)

A 33-year-old Japanese woman complaining of right-sided sciatica.

INTERVENTION(S)

Transgluteal computerized tomography (CT)-guided needle biopsy of a mass in the course of the right sciatic nerve was conducted for a histologic diagnosis.

MAIN OUTCOME MEASURE(S)

Histologic study with hematoxylin and eosin staining and CD10 immunohistochemical staining was performed.

RESULT(S)

Computerized tomography-guided biopsy was performed without any complication. CD10 staining distinguished endometrial stromal cells.

CONCLUSION(S)

Computerized tomography-guided biopsy followed by CD10 immunohistochemical staining is a minimally invasive procedure for accurate diagnosis of sciatic endometriosis.

Selected miscellaneous ovarian lesions: small cell carcinomas, mesothelial lesions, mesenchymal and mixed neoplasms, and non-neoplastic lesions

This contribution will cover a variety of uncommon tumors and tumor-like lesions of the ovary that can be associated with a myriad of diagnostic problems for the pathologist. A few of these lesions are not specific to the ovary and may be more common in the uterus or even extraovarian sites, but the mere knowledge that they also occasionally occur in, or involve, the ovary will facilitate their recognition by the pathologist. In contrast, the entity considered first, the highly malignant small cell carcinoma of hypercalcemic type, is an enigmatic tumor unique to the ovary.

CD10 expression in the female genital tract: does it have useful diagnostic applications?

In the female genital tract, CD10 was initially found to be expressed in endometrial stromal tumors of the uterus as well as in mesonephric remnants and related lesions and was thought to be helpful in distinguishing these tumors from their mimics. However, new studies have shown CD10 to be expressed in a wide range of tumors of the female genital tract, making this antibody of limited diagnostic value. This review discusses diagnostic applications of CD10 in the female genital tract, with emphasis on CD10 use in mesenchymal tumors of the uterus and in the differential diagnosis of mesonephric versus non-mesonephric carcinomas, where CD10 positivity alone may be misleading in the final classification of a tumor. CD10 may be useful in establishing the diagnosis of endometriosis (with the exception of the cervix), distinguishing metastatic renal clear cell carcinoma from a primary ovarian clear cell carcinoma, and distinguishing mesonephric hyperplasia from other benign glandular proliferations of the cervix.

CD10 immunohistochemical staining enhances the histological detection of endometriosis

OBJECTIVE

To determine whether the use of CD10 immunohistochemistry in addition to hematoxylin and eosin (H&E) staining would increase the sensitivity of surgically suspected endometriosis lesions.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care government research hospital.

PATIENT(S)

Thirty-one women with chronic pelvic pain.

INTERVENTION(S)

Immunohistochemical analysis for CD10 was performed on 108 possible endometriotic lesions and in the corresponding endometrial biopsy samples obtained during laparoscopy. When CD10 immunohistochemistry results were positive, the corresponding H&E section was reviewed to determine if the initial diagnosis should be revised.

MAIN OUTCOME MEASURE(S)

Histologic diagnosis of endometriosis by adjunctive use of CD10 immunohistochemistry in conjunction with H&E-stained specimens.

RESULT(S)

In endometrial stroma, CD10 was consistently present. Of the 70 specimens judged negative initially by H&E staining, CD10 staining led to the diagnosis of endometriosis in 11. The addition of CD10 immunohistochemistry detected more positive endometriosis lesions than H&E staining alone (45% vs. 35%). In three women with minimal endometriosis at surgery but initially negative histopathology, CD10 immunohistochemistry changed the histologic diagnosis to endometriosis.

CONCLUSION(S)

The adjunctive use of CD10 immunohistochemistry improves diagnostic sensitivity for endometriosis, especially for women with minimal disease.