Hormone receptor immunohistochemistry and human papillomavirus in situ hybridization are useful for distinguishing endocervical and endometrial adenocarcinomas

The evolving landscape of immunohistochemistry in cervical and uterine carcinoma in gynecologic oncology: current status and future directions

Immunohistochemistry (IHC) has become an indispensable tool in routine gynecological pathology, particularly with the advancements in molecular understanding and histological classification of gynecological cancers. This evolution has led to new immunostainings for diagnostic and classification purposes. This review describes the diagnostic utility of IHC in gynecological neoplasms, drawing insights from literature reviews, personal experiences, and research findings. It delves into the application of IHC in resolving morphologically equivocal cases, emphasizing its role in achieving an accurate diagnosis. The selection of appropriate immunomarkers for common scenarios encountered in gynecological pathology aids pathologists in navigating complex cases. Specifically, we focus on cervical and endometrial malignancies, elucidating the molecular rationale behind the use of specific immunohistochemical markers. An updated overview of essential immunohistochemical markers provides knowledge for precise diagnosis and classification of gynecological cancers. This review serves as a valuable resource for clinicians and researchers involved in the management and study of gynecological malignancies, facilitating improved patient care and outcomes.

Molecular Analysis of HPV-independent Primary Endometrial Squamous Cell Carcinoma Reveals TP53 and CDKN2A Comutations : A Clinicopathologic Analysis With Re-evaluation of Diagnostic Criteria

Human papillomavirus (HPV)-independent primary endometrial squamous cell carcinoma (PESCC) is a rare but aggressive subtype of endometrial carcinoma for which little is known about the genomic characteristics. Traditional criteria have restricted the diagnosis of PESCC to cases without any cervical involvement. However, given that modern ancillary techniques can detect HPV and characteristic genetic alterations that should identify the more common mimics in the differential diagnosis, including endometrial endometrioid carcinoma with extensive squamous differentiation and HPV-associated primary cervical squamous cell carcinoma, those criteria may benefit from revision. To further characterize PESCC, we identified 5 cases of pure squamous cell carcinoma dominantly involving the endometrium that had the potential to be PESCC: 1 case involving only the endometrium and 4 cases with some involvement of the cervix. Clinicopathologic features were assessed and immunohistochemical analysis (p16, estrogen receptor, progesterone receptor, and p53), HPV RNA in situ hybridization (high-risk and low-risk cocktails and targeted probes for 16 and 18), and molecular studies were performed. All tumors showed aberrant/mutation-type p53 expression, were negative for estrogen receptor, progesterone receptor, and p16, and had no detectable HPV. Per whole-exome sequencing, 4 of the 5 tumors demonstrated comutations in TP53 and CDKN2A (p16). Four patients died of disease within 20 months (range, 1 to 20 mo; mean, 9 mo), and 1 patient had no evidence of disease at 38 months. PESCC represents a unique, clinically aggressive subtype of endometrial cancer with TP53 and CDKN2A comutations. This characteristic profile, which is similar to HPV-independent squamous cell carcinoma of the vulva, is distinct from endometrioid carcinoma with extensive squamous differentiation and HPV-associated primary cervical squamous cell carcinoma and can be used to distinguish PESCC from those mimics even when cervical involvement is present. Diagnostic criteria for PESCC should be relaxed to allow for cervical involvement when other pathologic features are consistent with, and ancillary techniques are supportive of classification as such.

Utility of p63 and PTEN Staining in Distinguishing Cervical Microglandular Hyperplasia from Endometrial Endometrioid Carcinoma with Microglandular/Mucinous Features

Aims

Distinction between well‐differentiated endometrial carcinoma (EMCA) with microglandular/mucinous features and benign endocervical microglandular hyperplasia (MGH) can be a diagnostic challenge, especially when tissue is limited. The immunostains used to distinguish endocervical and endometrial carcinoma are less useful when the differential diagnosis is MGH. Here, we investigate the utility of p63 and phosphatase and tensin homologue (PTEN) to aid accurate classification.

Methods and results

Cases obtained from our pathology archives included 25 EMCA with mucinous/microglandular features, 26 MGH and nine atypical microglandular proliferations. Cases were assessed for glandular architecture, presence of mucinous and/or eosinophilic luminal secretions, subnuclear vacuoles, foamy histiocytes, inflammation, squamous metaplasia, cytological atypia and mitotic activity. The presence and pattern of immunohistochemical staining for p63 and PTEN was recorded. Microglandular proliferations with cytological atypia, mitotic activity, foamy histiocytes and complex glandular architecture were more commonly seen in EMCA, while small glands, bland nuclei and subnuclear vacuoles were enriched in MGH. All MGH cases displayed p63‐positive subcolumnar reserve cells and retained PTEN expression. Four EMCA cases showed non‐specific focal p63 staining either at the surface of the tumour or in areas of squamous differentiation. p63 and PTEN immunostains accurately predicted the final diagnosis for 3 atypical microglandular proliferation cases with follow‐up.

Conclusions

While there are morphological characteristics that differentiate EMCA and MGH, there is frequent overlap between these entities. Nonetheless, the pattern and extent of p63 and PTEN can aid accurate classification. Consistent p63‐positive subcolumnar reserve cells were seen only in MGH.

Estrogen receptor-positive adenocarcinoma of the cervix presenting during pregnancy: Two case reports and review of the literature

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Estrogen receptor or progesterone receptor positivity are unusual in cervical adenocarcinomas.

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Estrogen receptor positivity in pregnancy could be associated with a faster growth rate.

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Both patients presented remain free of recurrence after definitive treatment.

The incidence of adenocarcinoma of the cervix in pregnancy is exceptionally rare, and thus there is no consensus on its management. Here, we report two cases of adenocarcinoma of the cervix diagnosed in the context of pregnancy. In our first case, a patient referred to colposcopy for atypical glandular cells of undetermined significance was subsequently diagnosed with well differentiated endocervical adenocarcinoma on cone biopsy. Just prior to the cone biopsy, she was incidentally found to have a first trimester pregnancy loss. The patient subsequently underwent a radical hysterectomy and bilateral sentinel lymph node dissection. Final pathology revealed a stage 1B1 (FIGO 2009) well differentiated adenocarcinoma of the cervix. Interestingly, the tumour was positive for estrogen receptor, which is unusual for cervical adenocarcinoma.

In our second case, a patient presented with a pedunculated, exophytic cervical neoplasm at 31 weeks GA with self-limiting antepartum hemorrhage. The primary lesion measured 52 mm in diameter on MRI and was amputated at the base during the patient’s elective repeat cesarean section. Final pathology revealed a stage IB2 (FIGO 2009) mucinous adenocarcinoma of the cervix. The patient subsequently underwent a radical hysterectomy and bilateral pelvic lymph node dissection 17 weeks after initial presentation. The depth of invasion was 2.2 mm, restricted to the inner third of the cervical wall, and there was no lymphovascular space invasion in the surgical specimen. Surgical margins, parametria, and lymph nodes were all negative for adenocarcinoma. This tumour was also found to be estrogen receptor/progesterone receptor (ER/PR) positive, again unusual for cervical adenocarcinoma. P16 was strongly positive and HPV DNA studies were also positive for human papilloma virus 18. The patient received adjuvant external beam radiotherapy to the pelvis and currently remains in remission.

Immunohistochemistry in gynecologic carcinomas: Practical update with diagnostic and clinical considerations based on the 2020 WHO classification of tumors

This review provides an update on immunohistochemistry applications-diagnostic, prognostic, and predictive-in the pathology evaluation of gynecologic carcinomas. The 5th edition of the WHO Classification of Female Genital Tumors introduced important changes in the diagnostic classification of lower genital tract, endometrial, and ovarian carcinomas, with major influence on the routine pathology practice. Lower genital tract carcinomas and their precursor lesions are now classified based on their human papillomavirus (HPV)-associated and HPV-independent pathogenesis, reflecting the clinically significant prognostic differences and impacting the therapeutic decision-making. Immunohistochemical markers have an increasing role in the pathology evaluation of endometrial carcinomas: in addition to their traditional use in the differential diagnosis and histologic subtyping, they have also been recently advocated for prognostic classification as surrogates for the TCGA (The Cancer Genome Atlas) molecular groups. New entities - mesonephric-like adenocarcinoma and gastric (gastrointestinal)-type mucinous adenocarcinoma of the endometrium - have also been added and often require immunostains for diagnostic confirmation. Ovarian carcinomas frequently show overlapping morphologic patterns and heterogeneous appearance within the same tumor, necessitating immunohistochemical work-up. Beyond diagnostic applications, there is increasing clinical demand for screening of inherited cancer syndromes, prediction of prognosis and guiding targeted therapy. Practical issues and pitfalls related to mismatch repair protein immunohistochemistry, HER2, and PD-L1 testing are also discussed.

Feasibility of intravoxel incoherent motion diffusion-weighted imaging in distinguishing adenocarcinoma originated from uterine corpus or cervix

PURPOSE

To prospectively assess the incremental value of intravoxel incoherent motion (IVIM) DWI in determining whether the adenocarcinoma originated from the uterine corpus or cervix.

METHODS

Eighty consecutive uterine adenocarcinomas from the cervix or endometrium confirmed by histopathology underwent IVIM DWI acquisition on a 3.0T MR scanner before treatment. Five morphologic features were analyzed using Fisher exact test; IVIM DWI-derived parameters, including apparent diffusion coefficient (ADC), true coefficient diffusivity (D), perfusion-related diffusivity (D^*), and perfusion fraction (f) were compared using two-sample independent t-test or Mann-Whitney U test. Logistic regression analysis was used to develop different diagnosis model. The ROCs of these variables and diagnostic models were compared to evaluate the diagnostic efficiency.

RESULTS

Among single morphologic features, tumor location yielded the highest AUC of 0.891 in distinguishing endometrial adenocarcinoma (EAC) from cervical adenocarcinoma (CAC). Among single IVIM DWI-derived parameters, f values showed the best diagnostic performance (AUC: 0.837) at the optimal cut-off value of 0.261. Additionally, the combined diagnostic model, which consisted of tumor location, ADC and f showed the largest AUC of 0.967 with the highest sensitivity of 88.14%, highest specificity of 100.00%, and highest accuracy of 91.25%.

CONCLUSION

IVIM DWI-derived parameters add additional diagnostic value to conventional morphologic features. A combined diagnosis model is a promising imaging tool for predicting the origin of uterine adenocarcinoma, further contributing to therapeutic decision-making.

Differentiation of endometrial adenocarcinoma from adenocarcinoma of cervix using kinetic parameters derived from DCE-MRI

PURPOSE

This prospective study aimed to investigate the value of kinetic parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in differentiating uterine endometrioid adenocarcinoma (EAC) from adenocarcinoma of cervix (AdC).

METHODS

Seventy-five newly diagnosed patients with distinctive pathology underwent DCE-MRI. Observers independently calculated the tumor diameters and DCE-MRI parameters using both population and individual-based arterial input function (AIF). Inter-observer consistency was evaluated, and a comparative analysis between EAC (n = 47) and AdC (n = 28) was performed. Regression analysis was used to select parameters that best distinguished EAC from AdC, and to generate predictive models. Receiver operating characteristic curve (ROC) was applied to calculate the diagnostic efficiency of single parameter and the predictive models.

RESULTS

Inter-observer consistency was excellent (intra-class correlation [ICC] = 0.902-0.981), especially when calculated via population AIF with relatively higher ICC and smaller SD on Bland-Altman plot. Tumor diameters were not correlated with tumor types. All the DCE-MRI parameters were lower in EAC compared to AdC, except K_ep by population AIF and TTP by both sets of AIFs. The statistical parameters were V_e, Maxslop, and Maxconc by population AIF, and Maxslop and K^trans by individual AIF included in the predictive models, respectively. The two predictive models with combined parameters showed improved diagnostic efficiency in differentiating these two diseases compared with a single parameter.

CONCLUSION

DCE-MRI can quantitatively evaluate the perfusion difference between EAC and AdC, thus improving the identification of uterine adenocarcinoma with uncertain biopsy pathology.

A Comprehensive Review of Biomarker Use in the Gynecologic Tract Including Differential Diagnoses and Diagnostic Pitfalls

Morphologic (ie, hematoxylin and eosin) evaluation of the Mullerian tract remains the gold standard for diagnostic evaluation; nevertheless, ancillary/biomarker studies are increasingly utilized in daily practice to assist in the subclassification of gynecologic lesions and tumors. The most frequently utilized "biomarker" technique is immunohistochemistry; however, in situ hybridization (chromogenic and fluorescence), chromosomal evaluation, and molecular analysis can also be utilized to aid in diagnosis. This review focuses on the use of immunohistochemistry in the Mullerian tract, and discusses common antibody panels, sensitivity and specificity of specific antibodies, and points out potential diagnostic pitfalls when using such antibodies.

Diagnostic Algorithmic Proposal Based on Comprehensive Immunohistochemical Evaluation of 297 Invasive Endocervical Adenocarcinomas

The International Endocervical Adenocarcinoma Criteria and Classification was developed to separate endocervical adenocarcinomas (ECAs) into 2 main categories on the basis of morphology such as human papilloma virus-associated (HPVA) and non-human papilloma virus-associated adenocarcinomas. We aimed to improve the diagnostic accuracy of International Endocervical Adenocarcinoma Criteria and Classification by performing a comprehensive immunohistochemical evaluation and constructing objective immunohistochemical-based algorithms for the classification of these tumors. Tissue microarrays were constructed from 297 of 409 cases used to develop the original classification. Immunostains included p16, p53, estrogen receptor (ER), progesterone receptor, androgen receptor, Vimentin, CK7, CK20, HER2, HIK1083, MUC6, CA-IX, SATB2, HNF-1beta, napsin A, PAX8, CDX2, GATA3, p63, p40, and TTF-1. High-risk human papilloma virus (HR-HPV) was detected by in situ hybridization (ISH) using probes against E6 and E7 mRNA expressed in 18 different virus types. Vimentin, ER, and progesterone receptor were expressed in a significant minority of ECAs, mostly HPVAs, limiting their use in differential diagnosis of endometrioid carcinoma when unaccompanied by HPV-ISH or p16. HR-HPV ISH had superior sensitivity, specificity, and negative and positive predictive values compared with p16, as published previously. HNF-1beta did not have the anticipated discriminatory power for clear cell carcinoma, nor did MUC6 or CA-IX for gastric-type carcinoma. HNF-1beta and napsin A were variably expressed in clear cell carcinoma, with HNF-1beta demonstrating less specificity, as it was ubiquitously expressed in gastric-type carcinoma and in the majority of HPV-associated mucinous (predominantly intestinal-type and invasive ECA resembling stratified mucin-producing intraepithelial lesion [iSMILE]) and usual-type carcinomas. HIK1083 was expressed in nearly half of gastric-type carcinomas, but not in the vast majority of other subtypes. GATA3 was positive in 10% of usual-type adenocarcinomas and in single examples of other subtypes. Rare gastric-type and HPVA mucinous carcinomas displayed HER2 overexpression. Androgen receptor was positive in 6% of usual-type adenocarcinomas. Aberrant p53 expression was found in only 3.6% of usual-type HPVA carcinomas, but it was more prevalent in mucinous (intestinal type and iSMILE) HPVAs and non-human papilloma virus-associates (particularly in gastric-type carcinoma, >50% of cases). The following diagnostic classification algorithms were developed with the above data. Carcinomas without overt cytoplasmic mucin (endometrioid, usual-type endocervical, clear cell, and mesonephric carcinomas) can be subclassified using HR-HPV ISH, ER, and GATA3, whereas carcinomas with easily appreciated cytoplasmic mucin (endometrioid carcinoma with mucinous features, HPVA mucinous, and gastric-type carcinomas) can be subclassified with HR-HPV ISH and ER.

Guidelines to Aid in the Distinction of Endometrial and Endocervical Carcinomas, and the Distinction of Independent Primary Carcinomas of the Endometrium and Adnexa From Metastatic Spread Between These and Other Sites

In most cases of suspected endometrial neoplasia tumor origin can be correctly assigned according to a combination of clinical, radiologic, and pathologic features, even when the latter are based upon the examination of relatively small biopsy samples. However there are well-recognized exceptions to this rule which continue to create diagnostic difficulty, and sometimes difficulties persist even after the detailed examination of resection specimens. Among the most common problems encountered in practice are the distinction of primary endometrial and primary endocervical adenocarcinomas, and the determination of tumor origin when there is synchronous, multifocal involvement of gynecologic tract sites, for example the endometrium and the ovary. However, accurate diagnosis in these cases is important because this has significant staging, management and prognostic implications. In this review we discuss the value and limitations of key morphologic, immunophenotypic and molecular findings in these diagnostic scenarios.

Immunohistochemistry in Gynecologic Pathology: An Example-Based Practical Update

CONTEXT

- Immunohistochemical stains are routinely applied in the pathology diagnostic workup of gynecologic lesions. The rapidly expanding repertoire of available markers helps in refining the diagnostic criteria for each disease entity; however, limitations and pitfalls exist.

OBJECTIVE

- To provide a practical, relevant update on the use of immunohistochemistry for commonly encountered differential diagnoses in gynecologic pathology.

DATA SOURCES

- Literature review and authors' diagnostic experience.

CONCLUSIONS

- Immunohistochemistry is a helpful adjunct tool in gynecologic pathology. Although the primary application is in the diagnostic workup, novel prognostic and predictive markers, and immunostains to screen for genetic cancer syndromes, have also been recently introduced in the field.

Pathology of Endometrial Carcinoma

On a clinicopathological and molecular level, two distinctive types of endometrial carcinoma, type I and type II, can be distinguished. Endometrioid carcinoma, the typical type I carcinoma, seems to develop through an estrogen-driven "adenoma carcinoma" pathway from atypical endometrial hyperplasia/endometrioid intraepithelial neoplasia (AEH/EIN). It is associated with elevated serum estrogen and high body mass index and expresses estrogen and progesterone receptors. They are mostly low grade and show a favorable prognosis. A subset progresses into high-grade carcinoma which is accompanied by loss of receptor expression and accumulation of TP53 mutations and behaves poorly. Other frequently altered genes in type I carcinomas are K-Ras, PTEN, and ß-catenin. Another frequent feature of type I carcinomas is microsatellite instability mainly caused by methylation of the MLH1 promoter. In contrast, the typical type II carcinoma, serous carcinoma, is not estrogen related since it usually occurs in a small uterus with atrophic endometrium. It is often associated with a flat putative precursor lesion called serous endometrial intraepithelial carcinoma (SEIC). The molecular pathogenesis of serous carcinoma seems to be driven by TP53 mutations, which are present in SEIC. Other molecular changes in serous carcinoma detectable by immunohistochemistry involve cyclin E and p16. Since many of the aforementioned molecular changes can be demonstrated by immunohistochemistry, they are useful ancillary diagnostic tools and may further contribute to a future molecular classification of endometrial carcinoma as recently suggested based on The Cancer Genome Atlas (TCGA) data.

Three cases of women with HPV-related squamous cell carcinoma of unknown primary in the pelvis and retroperitoneum: A case series

Background

Carcinoma of unknown primary (CUP) of the pelvis is a challenging entity for the oncologist. The role of human papilloma virus (HPV)/p16 in carcinogenesis and prognosis is more established in the head and neck than in the pelvis. In the case of an HPV positive occult primary of the pelvis the radiation therapy target coverage is not well established.

Case reports

Case#1: A 69-year-old female with a left retroperitoneal and pelvic mass was treated with chemoradiation to a dose of 45 Gy in 25 fractions to elective lymph node regions and simultaneous boost to FDG-avid lymph nodes to 55 Gy in 25 fractions. A post-treatment PET-CT showed complete response of disease now 7 months post treatment. Case#2: A 58-year-old female with a large left retroperitoneal pelvic mass was treated post-operatively with chemoradiation to 45 Gy in 25 fractions with a pelvic boost to 54 Gy. She is clinically and radiographically with no evidence of disease at 4 years. Case#3: A 47-year-old female with left sided retroperitoneal pelvic mass that declined therapy. She ultimately died of progressive disease at 1 year after diagnosis.

Conclusion

Cisplatin based chemoradiation is effective for treating HPV/p16 + pelvic squamous cell cancers of unknown primary as long as the mass, regional lymph nodes and high risk pelvic primary sites are adequately covered.

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Adds 3 cases of pelvic squamous cell carcinoma of unknown primary

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Similarities between pelvic and head and neck squamous cell of unknown primary

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Radiation to highest risk sites of primary disease important

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Prognosis not as bad as previously shown with aggressive chemoradiation

Endocervical adenocarcinoma: selected diagnostic challenges

Endocervical adenocarcinomas can be classified into two main types of tumors, namely, those related to high-risk human papillomavirus and those unrelated to high-risk human papillomavirus. The former, representing the vast majority, are referred to as endocervical adenocarcinomas of usual type and the latter are dominated by the gastric-type mucinous adenocarcinomas. Commonly encountered diagnostic problems concerning these endocervical adenocarcinomas include: (1) diagnosing invasion for endocervical adenocarcinomas of usual type, particularly superficial forms which must be distinguished from extensive endocervical adenocarcinoma in situ; (2) distinguishing high-risk human papillomavirus-related endocervical adenocarcinomas from endometrial endometrioid carcinomas; and (3) distinguishing benign/hyperplastic mucinous endocervical glandular proliferations from gastric-type mucinous endocervical adenocarcinomas, particularly minimal deviation adenocarcinoma. The current review provides practical points and numerous illustrative examples to guide pathologists in addressing these diagnostic challenges in routine practice.

Adenocarcinoma of the cervix: should we treat it differently?

Worldwide, cervical cancer is a leading cause of mortality among women, causing 265,653 deaths annually. Squamous cell carcinoma (SCC) accounts for 75% of cervical cancer cases in the USA, while adenocarcinoma (AC) accounts for 25%. The incidence of SCC is decreasing in the USA, yet AC is increasing. Many differences exist between cervical SCC and AC including anatomic origin, risk factors, prognosis, dissemination, sites of recurrence, and rates of metastasis. Despite differences, current treatment algorithms do not distinguish between cervical SCC and AC. To date, prospective research directed toward AC is limited. We review published differences in response to neoadjuvant chemotherapy and concomitant chemotherapy with radiation, the role of adjuvant radical hysterectomy, and optimal chemotherapy for cervical AC. Cervical AC is sufficiently distinct from SCC to warrant specific treatment recommendations; however, lack of data evaluating AC limit recommendations. Additional prospective AC cervix specific research is needed.

Mesonephric carcinosarcoma involving uterine cervix and vagina: report of 2 cases with immunohistochemical positivity For PAX2, PAX8, and GATA-3

Mesonephric carcinomas are rare tumors predominantly arising in the uterine cervix from mesonephric remnants. Although the tumor has classic morphologic features, some cases can mimic Müllerian adenocarcinoma and be misdiagnosed, especially those with significant ductal pattern. Moreover, there is an overlap in immunohistochemical results with endometrial and endocervical carcinomas. In this study, we report 2 cases of mesonephric carcinosarcoma, originally diagnosed as Müllerian carcinomas, 1 presenting in the vagina; review immunohistochemical results including positivity for GATA-3, not previously reported and comment on the proposed panel of PAX8, p16, and estrogen receptors as discriminators of Müllerian adenocarcinoma (endocervical or endometrial) versus mesonephric carcinoma.

HPV-Related Retroperitoneal Squamous Cell Carcinoma of Unknown Primary: A Case Report

A 56-year-old female was referred to our hospital due to a mass measuring 5 cm in size in the left pelvic cavity, which was found incidentally during a health examination by ultrasonography. Exploratory laparotomy was performed and the mass was located at the left retroperitoneal parametrium without invasion of the uterus and ovary. The pathology report confirmed squamous cell carcinoma. Even after further studies, we did not find any other primary lesion. Human papillomavirus (HPV) DNA chip test (HPV 9G DNA Membrane Kit, Biometrixtechnology Inc.) showed that the surgical specimen was positive for HPV 18. She received adjuvant chemotherapy and would receive radiation therapy for the possibility of occult gynecologic cancer. Retroperitoneal squamous cell carcinoma of unknown primary is extremely rare and little is known about it. It is reported that HPV may be associated with the disease. Hence, the result of HPV test could have an impact on finding a suspicious primary lesion and treatment modality in this case.

The spectrum of cervical glandular neoplasia and issues in differential diagnosis

CONTEXT

Premalignant and malignant glandular lesions of the cervix are known to often cause diagnostic problems with a variety of benign (more common) as well as other malignant mimics, the latter setting often being represented by secondary involvement by endometrioid endometrial carcinoma especially in small samplings.

OBJECTIVE

To highlight key histologic features and immunohistochemical markers that may be helpful in the distinction of in situ endocervical carcinoma from benign glandular proliferations, and those that separate different subtypes of invasive endocervical carcinoma, as well as invasive carcinoma from other carcinomas secondarily involving the cervix and nonneoplastic proliferations of the cervix.

CONCLUSIONS

Clinical and morphologic features as well as immunohistochemistry results should be used in conjunction in the differential diagnosis of glandular proliferations of the cervix, as correct interpretation has major clinical consequences for the patient in most instances (especially benign versus malignant). Immunohistochemical markers should be used as part of a panel of antibodies, as exceptions may occur to the usual pattern of staining, and if used singly, they may mislead the pathologist to establish a wrong diagnosis.

Reliability of PAX8 in clinical practice to accurately determine primary site of origin in female pelvic or abdominal lesions

Female patients with gynecological malignancies can harbor peritoneal pelvic or abdominal lesions; however, other primary tumors can involve the peritoneum as well. Since sampling of the peritoneum now can be easily performed by fine needle aspiration or percutaneous biopsy, we have noticed an increase in such procedures as initial attempts to establish a diagnosis. PAX8 has been used alone or in combination with other tumor markers to accurately classify these lesions and determine primary site of origin; however, prior published studies determined expression of PAX8 within historically diagnosed cases. We reviewed the reliability of PAX8 to determine tumor type or primary site in 135 current clinical pelvic or abdominal lesions and highlight several pitfalls in its routine use, in particular, relying on the presumed expression pattern (positive or negative) within a given primary tumor and that poorly differentiated endometrial endometrioid carcinomas or undifferentiated carcinomas may have patchy PAX8 expression or even lose expression within the primary tumor or the metastasis.

MRI is highly specific in determining primary cervical versus endometrial cancer when biopsy results are inconclusive

AIM

To evaluate utility of magnetic resonance imaging (MRI) in determining the primary site of endometrial versus cervical tumours when the biopsy results are inconclusive.

MATERIAL AND METHODS

Forty-eight patients who underwent a total hysterectomy for unknown primary adenocarcinoma of the uterus after endometrial and/or endocervical biopsies were included in the study. The 48 available pelvic MRI images were reviewed by two body radiologists independently and jointly to resolve discordance, blinded to any clinical and pathological information. The clinical information and histopathology were reviewed by a radiology fellow and a pathologist specializing is gynaecological oncology. The final surgical pathology was used as the reference standard to confirm the origin of the primary tumour.

RESULTS

The radiologists correctly identified the primary sites in 85% of the cases (41/48). There was substantial agreement between the two readers (kappa statistics = 0.79). Both radiologists found that T2 and dynamic T1-weighted images (WI) were most helpful in making the diagnosis, and dynamic T1WI helped resolve problematic cases. The sensitivity and specificity for detecting endometrial and cervical cancer on MRI were 88% and 88% and 75% and 93%, respectively.

CONCLUSION

MRI has high sensitivity and specificity in determining the origin of the primary endometrial versus cervical tumours when endometrial/endocervical curettage is inconclusive.

Application of Immunohistochemistry and Molecular Diagnostics to Clinically Relevant Problems in Endometrial Cancer Bojana Djordjevic, Shannon Westin, Russell R. Broaddus

A number of different clinical scenarios are presented in which lab-based analyses beyond the usual diagnosis based on light microscopic examination of H&E stained slides - immunohistochemistry and PCR-based assays such as sequencing, mutation testing, microsatellite instability analysis, and determination of MLH1 methylation - are most helpful for guiding diagnosis and treatment of endometrial cancer. The central goal of this information is to provide a practical guide of key current and emerging issues in diagnostic endometrial cancer pathology that require the use of ancillary laboratory techniques, such as immunohistochemistry and molecular testing. The authors present the common diagnostic problems in endometrial carcinoma pathology, types of endometrial carcinoma, description of tissue testing and markers, pathological features, and targeted therapy.

Differentiating rectal carcinoma by an immunohistological analysis of carcinomas of pelvic organs based on the NCBI Literature Survey and the Human Protein Atlas database

The treatments and prognoses of pelvic organ carcinomas differ, depending on whether the primary tumor originated in the rectum, urinary bladder, prostate, ovary, or uterus; therefore, it is essential to diagnose pathologically the primary origin and stages of these tumors. To establish the panels of immunohistochemical markers for differential diagnosis, we reviewed 91 of the NCBI articles on these topics and found that the results correlated closely with those of the public protein database, the Human Protein Atlas. The results revealed the panels of immunohistochemical markers for the differential diagnosis of rectal adenocarcinoma, in which [+] designates positivity in rectal adenocarcinoma and [-] designates negativity in rectal adenocarcinoma: from bladder adenocarcinoma, CDX2[+], VIL1[+], KRT7[-], THBD[-] and UPK3A[-]; from prostate adenocarcinoma, CDX2[+], VIL1[+], CEACAM5[+], KLK3(PSA)[-], ACPP(PAP)[-] and SLC45A3(prostein)[-]; and from ovarian mucinous adenocarcinoma, CEACAM5[+], VIL1[+], CDX2[+], KRT7[-] and MUC5AC[-]. The panels of markers distinguishing ovarian serous adenocarcinoma, cervical carcinoma, and endometrial adenocarcinoma were also represented. Such a comprehensive review on the differential diagnosis of carcinomas of pelvic organs has not been reported before. Thus, much information has been accumulated in public databases to provide an invaluable resource for clinicians and researchers.

[Diagnosis and differential diagnosis of cervical adenocarcinoma]

This overview summarizes pathogenetic and practical aspects of (sub-)classification of cervical glandular (pre-)neoplasias and, inter alia, calls into question the usefulness of grading. In the context of the differential diagnosis of benign "imitations", the phenotypic variability of glandular precancerous lesions and carcinomas is described as well as the use of special tests to distinguish them. With regard to carcinomas, the differential diagnosis of well-differentiated neoplasias is addressed including "minimal deviation" adenocarcinoma (MDA, malignant adenoma), carcinomas with endometrioid or villoglandular morphology, and mesonephric hyper- and neoplasias. Furthermore, knowledge of HPV-negative glandular (pre-)neoplasias is covered including "gastric-type" adenocarcinomas and diagnostic algorithms for discriminating between primary and secondary cervical adenocarcinomas. Finally, comments are offered on the difficulties in recognizing early invasive adenocarcinomas, especially also the pitfalls inherent in determining the depth of invasion.

Endometrial carcinomas: a review emphasizing overlapping and distinctive morphological and immunohistochemical features

This review focuses on the most common diagnostic pitfalls and helpful morphologic and immunohistochemical markers in the differential diagnosis between the different subtypes of endometrial carcinomas, including: (1) endometrioid versus serous glandular carcinoma, (2) papillary endometrioid (not otherwise specified, villoglandular and nonvillous variants) versus serous carcinoma, (3) endometrioid carcinoma with spindle cells, hyalinization, and heterologous components versus malignant mixed müllerian tumor, (4) high-grade endometrioid versus serous carcinoma, (5) high-grade endometrioid carcinoma versus dedifferentiated or undifferentiated carcinoma, (6) endometrioid carcinoma with clear cells versus clear cell carcinoma, (7) clear cell versus serous carcinoma, (8) undifferentiated versus neuroendocrine carcinoma, (9) carcinoma of mixed cell types versus carcinoma with ambiguous features or variant morphology, (10) Lynch syndrome-related endometrial carcinomas, (11) high-grade or undifferentiated carcinoma versus nonepithelial uterine tumors. As carcinomas in the endometrium are not always primary, this review also discusses the differential diagnosis between endometrial carcinomas and other gynecological malignancies such as endocervical (glandular) and ovarian/peritoneal serous carcinoma, as well as with extra-gynecologic metastases (mainly breast and colon).

Atypical Endometrial Hyperplasia and Well Differentiated Endometrioid Adenocarcinoma of the Uterine Corpus

The distinction between atypical endometrial hyperplasia and well differentiated adenocarcinoma of the endometrium is one of the more difficult differential diagnoses in gynecologic pathology. Different pathologists apply different histologic criteria, often with different individual thresholds for atypical endometrial hyperplasia and grade 1 adenocarcinoma. While some classifications are based on a series of molecular genetic alterations (which may or may not translate into biologically or clinically relevant risk lesions), almost all current diagnostic criteria use a series of histologic features - usually a combination of architecture and cytology - for diagnosing atypical hyperplasia and adenocarcinoma. This article presents evidence-based histologic criteria for atypical endometrial hyperplasia and low grade endometrial carcinoma (both FIGO grade 1 and 2) with emphasis on common and not so common histologic mimics. Grade 3 endometrioid carcinoma is discussed in the Oliva and Soslow article in this publication.

Limited utility of magnetic resonance imaging in determining the primary site of disease in patients with inconclusive endometrial biopsy

OBJECTIVE

To evaluate the utility of preoperative magnetic resonance imaging (MRI) in determining whether primary disease site is cervical or endometrial in patients with inconclusive preoperative endometrial biopsy.

METHODS

We retrospectively identified all patients who underwent pelvic MRI and who had a preoperative diagnosis of cervical or endometrial cancer at MD Anderson Cancer Center between 1990 and 2006. The subset in which endometrial biopsy did not clarify the primary disease site was analyzed. Magnetic resonance imaging results were compared with postoperative histopathologic findings.

RESULTS

A total of 168 patients who underwent MRI who had a preoperative diagnosis of cervical or endometrial cancer were identified. Of these patients, 51 had an inconclusive endometrial biopsy. Magnetic resonance imaging suggested an endometrial primary tumor without cervical invasion in 28 patients, of whom 21 (75%) actually had such a tumor and 7 had an endometrial primary tumor with cervical invasion. Magnetic resonance imaging suggested an endometrial primary tumor with cervical invasion in 3 patients, all of whom had such a tumor. Magnetic resonance imaging suggested a cervical primary tumor in 6 patients, of whom 5 had such a tumor and 1 had an endometrial primary tumor without cervical invasion. Magnetic resonance imaging was inconclusive (did not clarify primary disease site or no lesion visualized) in 14 (27%) of 51 patients, 6 of whom had an endocervical primary tumor or an endometrial tumor with cervical involvement. Overall, preoperative MRI was either inaccurate or unhelpful in 22 (43%) of 51 patients.

CONCLUSION

Preoperative MRI in patients with inconclusive endometrial biopsy is inaccurate or unhelpful in nearly half of patients.

The presence of human papillomavirus or p16 in six cases of retroperitoneal carcinoma

OBJECTIVE

To describe six cases of unknown primary carcinoma of the retroperitoneum that were positive for human papillomavirus (HPV), a surrogate molecular marker for high-risk HPV (p16), or both.

METHODS

Using the MD Anderson pathology database, females with confirmed HPV or p16 expression within retroperitoneal carcinomas of unknown primary were identified. Clinical data were collected by retrospective chart review. One pathologist reviewed all histology. Individuals with known primary were excluded. Data regarding individual demographics, presentation, Pap test history, pathology, HPV and p16 positivity, and outcome were analyzed using descriptive statistics.

RESULTS

Six individuals were identified. The median age of the individuals was 43.5 years (range 27-54). Three malignancies (50%) were squamous and three (50%) were undifferentiated. Median follow-up was 12 months (range 6-48 months). Two of the six (33%) individuals had remote histories (more than 10 years) of abnormal Pap test results. All had normal gynecologic examination and Pap test results at diagnosis. Four tumors were HPV-positive (66%) and six were p16-positive (100%). All samples that were HPV-positive were also p16-positive. All individuals underwent treatment with chemotherapy, radiation, or both. One individual underwent initial attempt at resection that was unsuccessful. Two individuals are without evidence of disease, two have had progression of disease, and two have died of their disease.

CONCLUSION

Pelvic masses of unknown primary may be HPV-related despite normal cervical examinations.

LEVEL OF EVIDENCE

III.

A panel of 3 markers including p16, ProExC, or HPV ISH is optimal for distinguishing between primary endometrial and endocervical adenocarcinomas

Endometrial and endocervical adenocarcinomas may seem histologically identical and it can be difficult to determine primary site of origin based on morphology alone. As the distinction is significant and cannot always be made on the basis of clinical findings, various immunohistochemical panels have been proposed to aid in determining site of origin. Stains for vimentin, estrogen receptor (ER), progesterone receptor (PR), monoclonal carcinoembryonic antigen, p16 and ProExC, and HPV in situ hybridization (ISH), were performed on 283 tissue microarray (TMA) cores and 38 whole sections. The TMA consisted of 214 endometrial carcinomas, 33 endocervical adenocarcinomas, and 36 problematic cases. The endometrial and endocervical carcinomas represented usual endometrioid and mucinous types, and special variants (uterine serous carcinoma, uterine clear cell carcinoma, minimal deviation endocervical adenocarcinoma, cervical small cell carcinoma, adenoid basal cell carcinoma, mesonephric carcinoma). Univariate analysis showed that 6 markers (vimentin, ER, PR, p16, ProExC, and HPV ISH) performed well in distinguishing between endocervical and endometrial origin for the usual endometrioid and mucinous types. Multivariate analysis showed that vimentin, p16, and HPV ISH are the strongest predictors of site. Using a script written in R, the diagnostic accuracy of all possible combinations of markers was evaluated and it was shown that a 3 marker panel including vimentin, ER, or PR, and an HPV marker (p16, ProExC, or HPV ISH) is optimal for determining site of origin for usual endometrial and endocervical adenocarcinomas. However, these panels do not perform well with special variant carcinomas.

Endocervical adenocarcinomas with ovarian metastases: analysis of 29 cases with emphasis on minimally invasive cervical tumors and the ability of the metastases to simulate primary ovarian neoplasms

Most endocervical adenocarcinomas ( approximately 90%) are high-risk human papillomavirus (HPV)-related neoplasms, with the remainder being unrelated to HPV; both types infrequently metastasize to the ovaries. Clinicopathologic features of 29 cases of synchronous and metachronous endocervical and ovarian tumors (26 HPV-related, 3 unrelated to HPV) were analyzed. In 18 cases, the cervical tumors were clearly invasive; these included 5 clinically evident tumors diagnosed before the ovarian metastases (immediately preoperatively to 7 y), 11 clinically unsuspected tumors diagnosed concurrently in specimens obtained for evaluation of ovarian/pelvic masses, 1 case with concurrent clinically evident cervical and ovarian masses, and 1 clinically occult tumor diagnosed subsequent to the ovarian metastasis. In 11 cases, the cervical tumors were more limited; these included 5 tumors comprised predominantly of adenocarcinoma in situ with small foci of superficial invasion ("microinvasive carcinomas") diagnosed before the ovarian metastases (3 mo to 7 y) and 6 tumors comprised of extensive adenocarcinoma in situ lacking unequivocally recognizable stromal invasion diagnosed before (9 mo to 7 y, n=4), concurrently with (n=1), or subsequent to (n=1) the ovarian metastases. Fifteen cervical tumors involved lower uterine segment corpus endometrium or endomyometrium, including 4 tumors that were minimally invasive or not recognizably invasive in the cervix. The ovarian tumors ranged in size from 2.1 to 30.0 cm (mean/median=12.7/13.5); they were unilateral in 19 cases (65.5%) and 12 of these were unilateral and 10 cm or greater. In 26 cases, including the 19 unilateral tumors, the ovarian tumors exhibited "borderlinelike," confluent glandular, cribriform, and/or villoglandular patterns simulating primary ovarian atypical proliferative (borderline) tumors or well-differentiated carcinomas; these patterns were pure in 24 and admixed with minor infiltrative foci in 2. The ovarian tumors had features typical of metastases (bilateral and infiltrative) in only 3 cases. In all HPV-related cases the paired endocervical and ovarian tumors contained identical HPV types, establishing the ovarian tumors as metastases. Endocervical adenocarcinomas, including microinvasive forms and some not recognizably invasive, have the potential to metastasize to the ovaries; extension into the lower uterine segment/corpus endometrium may be a risk factor, with retrograde uterine/transtubal spread as a possible mechanism.

Low-grade endometrial adenocarcinoma: a diagnostic algorithm for distinguishing atypical endometrial hyperplasia and other benign (and malignant) mimics

The distinction between endometrial hyperplasia and well-differentiated adenocarcinoma of the endometrium continues to be a difficult differential diagnosis in surgical pathology. Evidence-based diagnostic criteria for well-differentiated endometrial adenocarcinoma focus on histologic features that predict myoinvasion in the hysterectomy specimen. Only 2 diagnostic criteria with significant power aid in this distinction: complex glandular architectural patterns (glandular confluence, intraglandular complexity, and hierarchical papillary architecture) and marked cytologic atypia beyond that typically defined as atypical hyperplasia (ie, prominent macronucleoli visible at low power and marked nuclear pleomorphism). Application of these 2 criteria in problematic endometrial proliferations allows stratification of patients into 3 risk categories: very low risk (< 0.05% risk of myoinvasion at hysterectomy)=complex atypical hyperplasia; intermediate risk (5.5% risk of myoinvasion at hysterectomy)=complex atypical hyperplasia, cannot exclude well-differentiated adenocarcinoma (borderline); and high risk (20% risk of myoinvasion at hysterectomy)=well-differentiated adenocarcinoma. In order to optimize the use of these diagnostic criteria, a variety of gland forming lesions that may mimic well-differentiated endometrioid adenocarcinoma must first be excluded. In addition, unusual morphologic patterns of low-grade endometrioid adenocarcinoma should be recognized, as they may cause confusion with other, higher grade (and therefore, more clinically aggressive) endometrial processes.

The utility of HPV in situ hybridization and the PAS test in improving the specificity of the diagnosis of CIN 1

The histologic features of cervical intraepithelial neoplasia (CIN 1), caused by infection by the human papillomavirus (HPV), can overlap with those of its mimics that can lead to an over diagnosis of this sexually transmitted disease. In this study, 67 consecutive cervical biopsies that were diagnosed as CIN 1 from the surgical files of Ohio State University Medical Center were analyzed. Twenty controls (10 CIN 1 cervical biopsies and 10 normal cervical tissues) were also studied. The 87 biopsies were reevaluated blinded to the original diagnosis and the results were correlated with detection of HPV DNA by in situ hybridization and glycogen by the periodic acid solution (PAS)/PAS-D stain, respectively. HPV was detected by in situ hybridization in 55/67 cases (82%); no virus was evident in the negative controls whereas each of the 10 CIN 1 controls was virus positive. A PAS test demonstrated in the mature squamous component of the negative controls a strong signal in cells with prominent and uniform halos, which was lost with diastase treatment, indicative of abundant glycogen. The PAS/PAS-D tests in the CIN 1 lesions showed rare variable sized glycogen deposits in the dysplastic cells. Nine (15%) cases initially diagnosed as CIN 1 were HPV negative by in situ hybridization and had halolike cells that were strongly and uniformly positive for glycogen. This data underscores the value of glycogen and HPV analyses in improving the specificity of the diagnosis of CIN 1.

Carcinoma of the lower uterine segment: a newly described association with Lynch syndrome

PURPOSE

Endometrial carcinoma in the lower uterine segment (LUS) is a poorly described cancer that can be clinically confused with endocervical carcinoma. We performed a case-comparison study to document the clinicopathologic characteristics of LUS tumors and their association with risk factors for endometrial cancer.

PATIENTS AND METHODS

The clinical records and pathology reports from women who underwent hysterectomy at our institution for endometrial or endocervical adenocarcinoma over an 11-year interval were reviewed. The LUS group consisted of women with endometrial tumors that clearly originated between the lower uterine corpus and the upper endocervix. Immunohistochemistry and microsatellite instability and MLH1 methylation assays were performed.

RESULTS

Thirty-five (3.5%) of 1,009 women had endometrial carcinoma of the LUS. Compared with patients with corpus tumors, LUS patients were younger, had higher stage tumors, and had more invasive tumors. Preoperative diagnosis of the LUS tumors more frequently included the possibility of endocervical adenocarcinoma. Seventy-three percent of the LUS tumors had an immunohistochemical expression pattern typical of conventional endometrioid adenocarcinoma. Ten (29%) of 35 women with LUS tumors were confirmed to have Lynch syndrome or were strongly suspected to have Lynch syndrome on the basis of tissue-based molecular assays.

CONCLUSION

The prevalence of Lynch syndrome in patients with LUS endometrial carcinoma (29%) is much greater than that of the general endometrial cancer patient population (1.8%) or in endometrial cancer patients younger than age 50 years (8% to 9%). On the basis of our results, the possibility of Lynch syndrome should be considered in women with LUS tumors.

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.

Prognosis of adenocarcinoma of the uterine cervix: p53 expression correlates with higher incidence of mortality

We investigated the significance of prognostic markers-estrogen receptor, progesterone receptor, p53, MIB-1 and bcl-2 - in adenocarcinoma of the uterine cervix. In 101 patients with primary cervical adenocarcinoma, treated from 1989 to 2000, we evaluated clinical parameters in relation to these prognostic markers. Mean age of patients was 45 years. Seventy eight percent of the patients were in FIGO stage I, 16% stage II, 7% stage III and IV. estrogen receptor, progesterone receptor, p53 and bcl-2 immunoreactivity was scored as 0 (up to 5% positive cells), 1+ (5-25% of cells positive), 2+ (26-50% of cells positive), 3+ (51-75% of cells positive) or 4+ (>76% of cells positive). MIB-1 was scored in 10 categories: 0-10, 11-20, 21-30, 31-40, 41-50, 51-60, 61-70, 71-80, 81-90, 91-100. The overall survival rate was 67%. Survival was not influenced by estrogen receptor, progesterone receptor, MIB-1, or bcl-2 strongly positive staining. Only p53 showed significant influence on survival, even when adjusted for stage or tumor grade. In conclusion, it does not seems useful to determine estrogen receptor, progesterone receptor, MIB-1 or bcl-2 in cervical adenocarcinomas as an indication of prognosis: survival is not influenced by presence or absence. However, if p53 staining is strongly positive survival is significantly worse than in tumors scored as negative or weak positive.

Immunohistochemistry as a diagnostic aid in cervical pathology

As with biopsies from other sites in the female genital tract, immunohistochemistry is now being increasingly used in cervical pathology as an aid to diagnosis. In this review, I discuss applications of immunohistochemistry in diagnostic cervical pathology with a particular focus on recent developments. It is emphasised that immunohistochemistry is to be used as an adjunct to routine morphological examination and that no marker is totally specific or sensitive for a given lesion. Although much of this review focuses on glandular lesions, the value of markers, such as MIB1 and p16, in the assessment of pre-invasive cervical squamous lesions is discussed. In the broad field of cervical glandular lesions, topics covered include: the value of markers such as MIB1, p16 and bcl-2 in distinguishing adenocarcinoma in situ and glandular dysplasia from benign mimics; markers of mesonephric lesions, including CD10; markers of value in the diagnosis of minimal deviation adenocarcinoma, such as HIK1083; markers of value in distinguishing metastatic cervical adenocarcinoma in the ovary from primary ovarian endometrioid or mucinous adenocarcinoma. Rarely ectopic prostatic tissue occurs in the cervix, which can be confirmed by positive staining with prostatic markers. A panel of markers, comprising oestrogen receptor, vimentin, monoclonal carcinoembryonic antigen and p16, is of value in distinguishing between a cervical adenocarcinoma and an endometrial adenocarcinoma of endometrioid type. Markers of use in the diagnosis of cervical neuroendocrine neoplasms, including small cell and large cell neuroendocrine carcinoma, are discussed. It is stressed that small cell neuroendocrine carcinomas may be negative with most of the commonly used neuroendocrine markers and this does not preclude the diagnosis. p63, a useful marker of squamous neoplasms within the cervix, is of value in distinguishing small cell neuroendocrine carcinoma (p63 negative) from small cell squamous carcinoma (p63 positive) and in confirming that a poorly differentiated carcinoma is squamous in type.

Immunohistochemical and functional biomarkers of value in female genital tract lesions

There has been a marked expansion in the literature pertaining to the use of immunohistochemical markers in female genital tract pathology, especially with regard to diagnosis. This review provides a survey of the antibodies commonly used in the diagnosis of gynecological lesions grouped as to function or type. Prognostic or predictive markers are also discussed where appropriate, although few of these are of value in everyday practice. It is stressed that when immunohistochemistry is used diagnostically, panels of markers provide better information than reliance on a single antibody.

Immunophenotypic diversity of endometrial adenocarcinomas: implications for differential diagnosis

Many endometrial adenocarcinomas, particularly those of endometrioid type, express estrogen receptors (ERs), progesterone receptors (PRs), and vimentin. This typical immunophenotype is frequently considered a standard against which others are compared when immunohistochemistry is used for differential diagnosis. We tested large numbers of endometrial cancers, enriched for high-grade tumors, to determine whether this reported immunophenotype was valid and whether expression differences between types of endometrial carcinoma could be exploited for diagnostic purposes. Immunohistochemical stains were performed on the following types of endometrial cancers using established methodology: International Federation of Gynecology and Obstetrics (FIGO) grades 1 and 2 endometrioid-42; FIGO grade 3 endometrioid-40; serous-24; clear cell-11; carcinosarcoma-9. In total, 92% of serous carcinomas expressed p16 strongly compared to weak-to-moderate expression of p16 in 7-67% of other tumors (FIGO grades 1 and 2 carcinoma and carcinosarcoma, respectively). A total of 84% of FIGO grades 1 and 2 carcinomas expressed ER compared to 9-54% of other tumors (clear cell and serous carcinomas respectively); 83% of FIGO grades 1 and 2 expressed PR compared to 11-54% of other carcinomas (carcinosarcoma and serous carcinoma, respectively). Most carcinomas were negative for monoclonal carcinoembryonic antigen (mCEA), and those that were positive showed mostly only focal membrane expression. Vimentin was expressed in nearly every tumor. Most tumors were diffusely vimentin positive, but a large range of expression patterns, from focal to diffuse and from weak to strong, was noted. Only 70% of FIGO grades 1 and 2 endometrioid carcinomas and 26% of grade 3 endometrioid carcinomas possessed the reportedly characteristic endometrial cancer immunophenotype p16 (-), ER (+), PR (+), mCEA (-), and vimentin (+). Endometrial cancers demonstrate substantial immunophenotypic diversity that remained apparent even within groups of similar histologic subtype and grade. ER, PR, and p16 expression was more illustrative of tumor type and degree of differentiation than they were of endometrial origin. In contrast, the vimentin-positive/CEA-negative phenotype remained the most constant among all endometrial cancers.

Immunohistochemistry for estrogen and progesterone receptors in the distinction of primary and metastatic mucinous tumors in the ovary: an analysis of 124 cases

Estrogen (ER) and progesterone receptor (PR) expression in primary ovarian mucinous tumors and the utility of these markers for distinguishing metastatic mucinous carcinomas in the ovary from primary ovarian mucinous tumors have not been extensively investigated. Immunohistochemical studies were performed on 124 mucinous tumors, including 52 primary ovarian tumors (30 atypical proliferative (borderline) mucinous tumors of gastrointestinal type, 11 atypical proliferative (borderline) mucinous tumors of seromucinous (endocervical-like) type, and 11 invasive mucinous carcinomas of usual (gastrointestinal) type) and 72 metastatic mucinous carcinomas in the ovary (primary sites: colorectum (24), pancreas (13), endocervix (eight), stomach (four), gallbladder/bile duct (four), appendix (four), and unknown (15)). All atypical proliferative mucinous tumors of gastrointestinal type, primary ovarian mucinous carcinomas, and metastatic mucinous carcinomas were negative for ER and PR with the exception of three metastatic endocervical adenocarcinomas which exhibited only weak expression of ER without PR. All atypical proliferative mucinous tumors of seromucinous type expressed ER to some degree and seven had some expression of PR. Immunohistochemical assessment of hormone receptor expression is of no value in distinguishing the common types of primary ovarian mucinous tumors (atypical proliferative mucinous tumors of gastrointestinal type and mucinous carcinomas of usual type) from the vast majority of mucinous carcinomas metastatic to the ovary. The above observations on hormone receptor expression in primary ovarian mucinous tumors support the concept that atypical proliferative (borderline) mucinous tumors of gastrointestinal and seromucinous (endocervical-like) types are distinctive tumors.

Pseudoinfiltrative Tubal Metaplasia of the Endocervix: A Potential Form of In Utero Diethylstilbestrol Exposure-Related Adenosis Simulating Minimal Deviation Adenocarcinoma

We report three cases of unusual tubal-type endocervical glandular proliferations simulating minimal deviation adenocarcinoma in women with a history of in utero diethylstilbestrol (DES) exposure. The lesions were characterized by haphazard glandular proliferations extending from 3.4 to 6.1 mm into the endocervical stroma and to the margins of excision in all cases. Most of the glands were small to medium-sized and round; some exhibited a moderate degree of cystic dilatation, and occasional glands had curvilinear profiles. The glandular epithelium displayed extensive tubal-type differentiation in all cases. In two cases, the glands lacked cytologic atypia and mitotic activity, and in one case, there was mild to moderate nuclear atypia with occasional mitotic activity. Immunohistochemical studies showed diffuse expression of estrogen and progesterone receptors and essentially no expression of p16 in two cases tested; there was no expression of CD10 in one case that was tested. The Ki-67 proliferation index was zero in one case and 25% in another. Human papillomavirus DNA was not detected by in situ hybridization in one case that was tested. The proliferations lacked features of mucinous and tubo-endometrioid types of minimal deviation adenocarcinoma. The clinicopathologic findings suggest the lesions are benign, and the association with in utero DES exposure raises the possibility that these could be a form of DES-related adenosis.