Issues in the Differential Diagnosis of Uterine Low-grade Endometrioid Carcinoma, Including Mixed Endometrial Carcinomas: Recommendations from the International Society of Gynecological Pathologists.

This article provides practical recommendations developed from the International Society of Gynecological Pathologists Endometrial Carcinoma Project to address 4 issues that may arise in the diagnosis of uterine corpus low-grade endometrioid carcinoma: (1) The distinction between atypical hyperplasia and low-grade endometrioid carcinoma. (2) The distinction between low-grade endometrioid carcinoma and serous carcinoma. (3) The distinction between corded and hyalinized or spindle cell variants of low-grade endometrioid carcinoma and carcinosarcoma. (4) The diagnostic criteria for mixed endometrial carcinomas, a rare entity that should be diagnosed only after exclusion of a spectrum of tumors including morphologic variants of endometrioid carcinoma, dedifferentiated endometrial carcinoma, carcinosarcoma, and endometrial carcinomas with ambiguous morphology.

High-grade Endometrial Carcinomas: Morphologic and Immunohistochemical Features, Diagnostic Challenges and Recommendations.

This review of challenging diagnostic issues concerning high-grade endometrial carcinomas is derived from the authors' review of the literature followed by discussions at the Endometrial Cancer Workshop sponsored by the International Society of Gynecological Pathologists in 2016. Recommendations presented are evidence-based, insofar as this is possible, given that the levels of evidence are weak or moderate due to small sample sizes and nonuniform diagnostic criteria used in many studies. High-grade endometrioid carcinomas include FIGO grade 3 endometrioid carcinomas, serous carcinomas, clear cell carcinomas, undifferentiated carcinomas, and carcinosarcomas. FIGO grade 3 endometrioid carcinoma is diagnosed when an endometrioid carcinoma exhibits >50% solid architecture (excluding squamous areas), or when an architecturally FIGO grade 2 endometrioid carcinoma exhibits marked cytologic atypia, provided that a glandular variant of serous carcinoma has been excluded. The most useful immunohistochemical studies to make the distinction between these 2 histotypes are p53, p16, DNA mismatch repair proteins, PTEN, and ARID1A. Endometrial clear cell carcinomas must display prototypical architectural and cytologic features for diagnosis. Immunohistochemical stains, including, Napsin A and p504s can be used as ancillary diagnostic tools; p53 expression is aberrant in a minority of clear cell carcinomas. Of note, clear cells are found in all types of high-grade endometrial carcinomas, leading to a tendency to overdiagnose clear cell carcinoma. Undifferentiated carcinoma (which when associated with a component of low-grade endometrioid carcinoma is termed "dedifferentiated carcinoma") is composed of sheets of monotonous, typically dyscohesive cells, which can have a rhabdoid appearance; they often exhibit limited expression of cytokeratins and epithelial membrane antigen, are usually negative for PAX8 and hormone receptors, lack membranous e-cadherin and commonly demonstrate loss of expression of DNA mismatch repair proteins and SWI-SNF chromatin remodeling proteins. Carcinosarcomas must show unequivocal morphologic evidence of malignant epithelial and mesenchymal differentiation.

Current Chemotherapy and Potential New Targets in Uterine Leiomyosarcoma.

A variety of chemotherapeutic agents have been used for treating recurrent or advanced stage uterine leiomyosarcoma (ULMS). The response rates of these current agents are disappointing, with partial response rates varying from 0% to 33%, and complete response rates varying from 0% to 8%. Recent studies have documented many molecular changes in ULMSs. Prominent amongst these are gains of growth factors C-MYC, Bcl-2, K-ras, and Ki-67, and losses in tumor suppressors p16, p53, Rb1, ING2 and D14S267. Various techniques that have been used to target these molecules are presented. Targeting specific therapies at these underlying molecular changes could potentially yield better response rates with fewer side effects.

Neutrophils Oppose Uterine Epithelial Carcinogenesis via Debridement of Hypoxic Tumor Cells.

Polymorphonuclear neutrophils (PMNs) are largely considered to foster cancer development despite wielding an arsenal of cytotoxic agents. Using a mouse model of PTEN-deficient uterine cancer, we describe a surprising inhibitory role for PMNs in epithelial carcinogenesis. By inducing tumor cell detachment from the basement membrane, PMNs impeded early-stage tumor growth and retarded malignant progression. Unexpectedly, PMN recruitment and tumor growth control occurred independently of lymphocytes and cellular senescence and instead ensued as part of the tumor's intrinsic inflammatory response to hypoxia. In humans, a PMN gene signature correlated with improved survival in several cancer subtypes, including PTEN-deficient uterine cancer. These findings provide insight into tumor-associated PMNs and reveal a context-specific capacity for PMNs to directly combat tumorigenesis.

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.

Massive ovarian edema associated with a broad ligament leiomyoma: a case report and review.

Massive ovarian edema is a rare disorder in which there is marked accumulation of interstitial fluid in the stroma of the ovary. Grossly, the involved ovary is an enlarged solid mass with a smooth tan-white surface, easily confused with a neoplasm. Microscopically, it features diffuse interstitial edema sparing follicles and outer cortex, dilated lymphatic vessels, thick-walled veins, fibromatosis, and luteinized stromal cells. It is believed that massive ovarian edema arises from interference in lymphatic drainage and venous return of the ovary secondary to partial torsion among other etiologies. Herein we provide the first description of unilateral ovarian edema in association with a large leiomyoma in the ipsilateral broad ligament. It is important to recognize the various presentations of this benign entity and to consider it in the differential diagnosis of an adnexal mass in a reproductive age woman.

MED12 and HMGA2 mutations: two independent genetic events in uterine leiomyoma and leiomyosarcoma.

Recent identification of somatic MED12 mutations in most uterine leiomyomas brings a new venue for the study of the tumorigenesis of leiomyomas. We are particularly interested in the correlation of MED12 and HMGA2 gene products in leiomyomas and leiomyosarcomas with and without MED12 mutations. To address these issues, in this study we examined MED12 mutations in a large cohort of usual type leiomyomas (178 cases) and uterine leiomyosarcomas (32 cases). We found that 74.7% (133/178) of leiomyomas had MED12 mutations, which was consistent with several independent studies. In contrast, only 9.7% (3/32) of leiomyosarcomas harbored MED12 mutations. Expression analysis by western blot and immunohistochemistry revealed that those leiomyomas with complex MED12 mutations had significantly lower protein products than the matched myometrium. Interestingly, most leiomyosarcomas without MED12 mutations also had very low levels of MED12 expression in comparison to the matched myometrium. These findings suggest a potential functional role of MED12 in both benign and malignant uterine smooth muscle tumors. When we further examined HMGA2 expression in all leiomyomas and leiomyosarcomas, we found that HMGA2 overexpression was exclusively present in those leiomyomas with no MED12 mutation, accounting for 10.1% (18/178) of total leiomyomas and 40% (18/45) of non-MED12 mutant leiomyomas. Twenty-five percent (8/32) of leiomyosarcomas had HMGA2 overexpression, and no MED12 mutations were found in HMGA2 positive leiomyosarcoma. These findings strongly suggest that MED12 mutations and HMGA2 overexpression are independent genetic events that occur in leiomyomas, and they may act differently in the tumorigenesis of uterine leiomyomas.

Diagnostic criteria for distinguishing endometrial adenocarcinoma from complex atypical endometrial hyperplasia.

Morphologic criteria for distinguishing endometrial adenocarcinoma from complex atypical endometrial hyperplasia have been described previously, but they have not been examined extensively for their individual ability for predicting endometrial adenocarcinoma as determined by subsequent hysterectomy. We examined endometrial biopsies diagnosed in the spectrum of complex atypical endometrial hyperplasia to well-differentiated endometrial adenocarcinoma for various morphologic features that may be predictive for the presence of myoinvasive endometrial adenocarcinoma in subsequent hysterectomy. Cases diagnosed as FIGO grade I endometrial adenocarcinoma or complex atypical endometrial hyperplasia in endometrial biopsies seen at New York University Medical Center from 2003 to 2006 were analyzed for the presence of various morphologic features without the knowledge of hysterectomy findings. Only those cases with subsequent hysterectomy were included in the study. The data were analyzed to identify features with high specificity for a finding of myoinvasive endometrial adenocarcinoma in subsequent hysterectomy. Extreme glandular crowding (95% or greater area with glands, aggregate size 3 mm or greater) and cribriform foci of any size were found to have high sensitivity and specificity for the finding of myoinvasive carcinoma in subsequent hysterectomy (P < .0001).

Triple synchronous primary gynecologic carcinomas: a case report and review of the literature.

Double synchronous primaries are known to occasionally occur in gynecologic cancers. Cases of triple or quadruple synchronous primaries, with only 4 case reports in the literature, are extremely rare. The authors report the case of a 49-year-old para 2-0-0-2 woman who presented for surgical management of metastatic ovarian adenocarcinoma diagnosed at an outside institution. On examination of the surgical specimen, 3 synchronous primary carcinomas with multiple histologic features were identified within the ovaries, uterus, and cervix. Although rare, the possibility of triple synchronous primary malignancies should be considered when evaluating gynecologic malignancies.

MIB-1 (Ki-67), estrogen receptor, progesterone receptor, and p53 expression in atypical cells in uterine symplastic leiomyomas.

Nine cases of symplastic uterine leiomyomas were chosen from our files using strict criteria. An immunochemical study of the expressions of Ki-67, estrogen receptor, progesterone receptor, and p53 was performed. For each antigen, the percentages of positive atypical (bizarre) cells and nonatypical cells were compared. Both groups had identical and fairly high estrogen receptor and progesterone receptor immunohistochemical profiles and very low levels of p53 expression. The atypical cells had significantly higher percentages of cells expressing Ki-67 compared with nonatypical cells (17+/-20% vs. 3+/-3.9%). Therefore, rather than being degenerative in nature, the atypical cells are actively proliferating.

Let-7 repression leads to HMGA2 overexpression in uterine leiomyosarcoma.

Overexpression of HMGA2 is common in uterine leiomyomas (ULM). The expression of HMGA2 in its malignant counterpart - uterine leiomyosarcomas (ULMS) remains undetermined. Recently it has been shown that repression of HMGA2 by microRNA let-7s is a critical molecular regulatory mechanism associated with tumour growth in many tumours and cell types, including leiomyomas. To test whether HMGA2 and let-7s play a role in ULMS, we examined the levels of endogenous HMGA2 and let-7 expression and found a significant correlation between these two molecules in a case-matched cohort of human ULMS. We found that overexpression of HMGA2 and let-7-mediated HMGA2 repression is a relevant molecular alteration in ULMS. Disrupting the control of HMGA2 and let-7 pairs promotes ULMS cell growth in vitro.

Molecular and immunohistochemical evidence for the origin of uterine leiomyosarcomas from associated leiomyoma and symplastic leiomyoma-like areas.

It is uncertain whether uterine leiomyosarcoma arises de novo or in preexisting leiomyoma. Leiomyoma-like areas can be seen associated with uterine leiomyosarcoma, raising the possibility of precursor lesions for uterine leiomyosarcoma. In this study, we examined cases of uterine leiomyosarcoma associated with leiomyoma-like areas at the histological, immunohistochemical and DNA level to further evaluate if benign-looking leiomyoma-like and uterine leiomyosarcoma areas are related. Cases of uterine leiomyosarcoma observed at the New York University Medical Center from 1994 to 2007 were reviewed for the presence of leiomyoma-like areas. Of the 26 cases of uterine leiomyosarcoma observed during this period, 18 cases had an associated leiomyoma-like area (five cellular leiomyoma, four symplastic leiomyoma, four cellular and symplastic leiomyoma and five usual type leiomyoma). Sixteen of the 18 cases were examined immunohistochemically for Ki-67, for estrogen receptor, progesterone receptor and for p53. Immunohistochemical profiles were as expected for leiomyoma-like (the mean expression of p53, ER, PR and Ki-67 at 0.3, 63, 75 and 0.6%, respectively), symplastic leiomyoma-like areas (the mean expression of p53, ER, PR and Ki-67 at 0.6, 85, 89 and 5.5%, respectively) and uterine leiomyosarcoma areas (the mean expression of p53, ER, PR and Ki-67 at 52, 38, 39 and 61%, respectively). In six cases, the leiomyoma-like and uterine leiomyosarcoma areas from each case were examined using high-density oligonucleotide array-CGH to determine genetic aberrations in the two areas. Nearly all the genetic aberrations found in leiomyoma-like areas were also found in the corresponding uterine leiomyosarcoma areas. In addition, uterine leiomyosarcoma areas had additional genetic aberrations. The immunohistochemical profiles and genetic aberrations of the examined cases suggest that uterine leiomyosarcoma could arise from the preexisting leiomyoma-like areas that often have a symplastic or cellular morphology.

A deficit in biopsying potentially premalignant oral lesions in Puerto Rico.

BACKGROUND: Intraoral lesions clinically suspicious for cancer/precancer should be biopsied and diagnosed histopathologically. We evaluated whether the frequency of oral cancer (OC) cases diagnosed in Puerto Rico (PR) is disproportionately high relative to the frequency of persons with histopathologic diagnoses that would have appeared clinically suspicious for OC/precancer at biopsy. METHODS: All pathology reports for oral (ICD-O-3 C01-C06) soft tissue biopsies generated during 1/2004-5/2005 by seven PR and two New York City (NYC) pathology laboratories were reviewed. The analysis was restricted to persons diagnosed with invasive oral squamous cell carcinoma (OSCC), epithelial dysplasia, or hyperkeratosis/epithelial hyperplasia (HK/EH), i.e., diagnoses associated with lesions clinically suspicious for OC/precancer. The OC relative frequency measured the percentage of persons diagnosed with OSCC among persons with OSCC, dysplasia, or HK/EH. OC relative frequencies for PR and NYC laboratories were compared. RESULTS: Overall, the OC relative frequency was 67% in PR and 40% and 4% in the NYC general and oral pathology laboratories, respectively (each p<0.001). In PR, the OC relative frequency was highest for males (80%). When OC relative frequencies were stratified by pathology laboratory type (general/oral) and compared across PR and NYC, age/gender-specific OC relative frequencies were always higher in PR; however, differences were consistently statistically significant for males only. CONCLUSION: A disparity in the OC relative frequency exists in PR vs. NYC indicating a shortfall in biopsying potentially precancerous oral lesions in PR. PR residents with intraoral lesions suspicious for oral cancer/precancer are most likely to be biopsied only after developing an invasive OC.

Presence of endometrial adenocarcinoma in situ in complex atypical endometrial hyperplasia is associated with increased incidence of endometrial carcinoma in subsequent hysterectomy.

The distinction of complex atypical endometrial hyperplasia from endometrial adenocarcinoma is often problematic. Foci of back-to-back arrangement of glands or foci of cribriform arrangement of glands smaller than 2.1 mm in diameter are considered insufficient for the diagnosis of endometrial adenocarcinoma by some authors, and sufficient to be diagnosed as endometrial adenocarcinoma by other authors. We refer to these foci as endometrial adenocarcinoma in situ. In this study, we evaluated findings in subsequent hysterectomy in complex atypical endometrial hyperplasia patients with and without adenocarcinoma in situ. Follow-up findings, including the presence or absence of endometrial adenocarcinoma in the hysterectomy specimen, the grade of the carcinoma and the depth of myometrial invasion were analyzed. Of the total 87 patients with complex atypical endometrial hyperplasia, 33 patients had adenocarcinoma in situ and 54 lacked adenocarcinoma in situ. Of 33 patients 22 (66%) with adenocarcinoma in situ had endometrial adenocarcinoma on subsequent hysterectomy vs 13 of 54 (24%) patients without adenocarcinoma in situ (P=0.0001). Myoinvasive endometrial adenocarcinoma was present in 20 of 33 (61%) patients with adenocarcinoma in situ vs 8 of the 54 (15%) patients without adenocarcinoma in situ (P< or =0.0001). The depth of myometrial invasion in cases with myoinvasion was 24.5+19.4% in patients with adenocarcinoma in situ and 12.8+8.5% in patients without adenocarcinoma in situ (P=0.05). Among patients younger than age of 50, 5 of the 7 (71%) with adenocarcinoma in situ had myoinvasive carcinoma vs 2 of the 13 (15%) without adenocarcinoma in situ (P=0.02). The likelihood of finding endometrial adenocarcinoma in subsequent hysterectomy in patients with complex atypical endometrial hyperplasia is significantly increased if adenocarcinoma in situ is present in prior endometrial sampling. Endometrial adenocarcinomas in patients with adenocarcinoma in situ are far more frequently myoinvasive, and invade to a greater depth than endometrial adenocarcinomas seen in patients without adenocarcinoma in situ. Use of adenocarcinoma in situ terminology could lead to improved management of patients with complex atypical endometrial hyperplasia.

Expression of insulin-like growth factors (IGFs) and IGF signaling: molecular complexity in uterine leiomyomas.

OBJECTIVE: To study whether dysregulation of insulin-like growth factors (IGFs) and IGF signaling are common molecular changes in symptomatic leiomyomas (fibroids) and whether IGFs are associated with large fibroids. DESIGN: Examination of IGFs and IGF pathway genes in a large cohort of fibroids at transcriptional and translational levels. Mechanisms leading to alterations of IGFs and related genes were also analyzed. SETTING: University clinical research laboratory. PATIENT(S): Hysterectomies for symptomatic fibroids were collected: 180 cases from paraffin-embedded tissues and 50 cases from fresh-frozen tissues. INTERVENTION(S): Tissue microarray and immunohistochemistry, DNA methylation analysis, reverse-transcriptase polymerase chain reaction, and Western blot. MAIN OUTCOME MEASUREMENT(S): Transcription and translation analyses of IGF-1/2, p-AKT, p-S6K, and TSC1/2 in fibroids and matched myometrium. RESULT(S): Insulin-like growth factors and downstream effectors were dysregulated in approximately one third of fibroids. All except for IGF-2 seemed to be abnormally regulated at translation levels. Up-regulation of IGF-2 messenger RNAs was contributed by all four alternating slicing promoters. There was a positive correlation of IGF-1 and p-AKT over-expression with fibroid size. Insulin-like growth factor 1 but not IGF-2 levels directly correlated with activation of p-AKT and p-S6K. CONCLUSION(S): Altered expressions of IGFs and their related downstream proteins were found in one third of fibroids. Large fibroids show high levels of IGF-1 and p-AKT activity compared with small ones.

Antiproliferative effects by Let-7 repression of high-mobility group A2 in uterine leiomyoma.

High-mobility group A2 (HMGA2) is commonly overexpressed in large leiomyomas. HMGA2 is an important regulator of cell growth, differentiation, apoptosis, and transformation. As a predicted target of Let-7 microRNAs (Let-7s), HMGA2 can be repressed by Let-7s in vitro. MicroRNA profiling analysis revealed that Let-7s were significantly dysregulated in uterine leiomyomas: high in small leiomyomas and lower in large leiomyomas. To evaluate whether Let-7 repression of HMGA2 plays a major role in leiomyomas, we analyzed the molecular relationship of HMGA2 and Let-7s, both in vitro and in vivo. We first characterized that exogenous Let-7 microRNAs could directly repress the dominant transcript of HMGA2, HMGA2a. This repression was also identified for two cryptic HMGA2 transcripts in primary leiomyoma cultures. Second, we found that the endogenous Let-7s were biologically active and played a major role in the regulation of HMGA2. Then, we illustrated that Let-7 repression of HMGA2 inhibited cellular proliferation. Finally, we examined the expression levels of Let-7c and HMGA2 in a large cohort of leiomyomas (n = 120), and we found high levels of Let-7 and low levels of HMGA2 in small leiomyomas, and low levels of Let-7 and high levels of HMGA2 in large leiomyomas. Our findings suggest that the Let-7-mediated repression of HMGA2 mechanism can be an important molecular event in leiomyoma growth.

Application of immunohistochemistry to gynecologic pathology.

CONTEXT: A large variety of tumors and lesions arise in the female genital tract. Although the majority of these can be correctly recognized on routine hematoxylin-eosin-stained slides, occasional cases present a diagnostic challenge. Immunohistochemical stains are extremely useful in resolving many of these problematic cases. As the knowledge in this area is constantly expanding, it is useful to have this updated information in a review form for easy access. OBJECTIVE: To present our current knowledge of immunohistochemistry of the lesions of the female genital tract in a readily accessible form. DATA SOURCES: The review is based on previously published articles on this topic. CONCLUSIONS: Immunohistochemical stains help in reaching a conclusive diagnosis in a variety of problematic lesions seen in gynecologic pathology. As in any other system, immunohistochemical findings need to be interpreted in light of the clinical history and morphologic findings.