P53 Immunostaining Research Articles

Immunohistochemical Expression of p16 in Melanocytic Lesions: An Updated Review and Meta-analysis.

- Making an accurate diagnosis for melanocytic lesions has always been challenging for pathologists, especially when dealing with difficult-to-diagnose cases. Misdiagnosis of melanoma and melanocytic lesions in general has tremendous medical-legal implications, often leading to unnecessary and excessive use of adjunctive tests. Although molecular testing is of much interest and there is great support for its development, currently, for most melanocytic lesions, immunohistochemical studies remain the most practical method for assistance in the routine diagnosis of melanocytic lesions for the average pathologist. - To review the practical use of p16 immunohistochemistry for evaluating melanocytic lesions, particularly for differentiating benign from malignant tumors, and to perform a meta-analysis of primary studies evaluating p16 immunohistochemistry in melanocytic lesions. - A PubMed database search for literature reporting melanocytic lesions and p16 immunohistochemistry was performed. Essential information from each study (number of samples, antibody used, collection dates, overall p16 immunohistochemistry results, and general method of interpretation) was tabulated and analyzed. Examples of representative cases showing p16 immunostaining pattern are also illustrated. - Incorporation of p16 immunohistochemistry for the diagnosis of melanocytic lesions is of limited use, especially for the purpose of differentiating benign from malignant lesions. Evaluation of multiple studies reveals a wide range of results. However, there appears to be some value for the use of p16 in distinguishing nodal nevi from metastatic melanoma within nodes. The method of interpretation (nuclear versus cytoplasmic staining) also appears to give differing results, as studies considering only nuclear staining appeared to show more consistent results from study to study.

Comparison of nuclear P16 immunostaining in atypical and normal endocervical glands: A descriptive analytical study

Background: Cervical cancer is one of the most common malignancies worldwide and a major problem in the healthcare system. Nowadays, the importance of biomarkers in the diagnosis of malignancies is proven. Some studies have pointed to the role of P16 in the diagnosis of cervical cancer. The purpose of this study was to compare the nucleic reactivity with P16 antibody in atypical vs normal endocervical glands. Methods: We enrolled 60 patients who had undergone the hysterectomy due to non-endocervical causes at Alzahra University Hospital of Tabriz University of Medical Sciences to a descriptive-analytical study. We selected 25 patients with atypical endocervical glands and 35 subjects with normal glands based on the pathologic examination using hematoxylin-eosin staining. Then, we assessed the frequency of nucleic reactivity of the tissues with P16 antibody in both groups. Results: No P16 expression was observed in any of the samples from normal subjects. However, only 2 (8.0%) out of 25 samples from the atypical group, were not reactive to the P16 antibody. Also, 20 samples (80.0%) were diffusely stained continuous, whereas three samples (12.0%) were stained locally. Accordingly, in the group with atypical endocervical glands, the reaction with P16 antibody was significantly higher than that of normal endocervical glands (p= 0.001). Conclusion: P16 biomarker may play a role in the pathogenesis and progression of cervical cancer and can be used as a diagnostic marker for this purpose.

Fluorescent In Situ Hybridization for TP53 in the Diagnosis of Pediatric Osteogenic Sarcoma.

Osteogenic sarcoma (OS) is the most common malignant bone tumor in children and adolescents. Despite advances in molecular genetic characterization of pediatric and adult tumors, the diagnosis of OS still depends almost entirely on light microscopy. The lack of consistent genetic changes in OS has greatly hindered the development of any diagnostic molecular test. Recently, whole-genome sequencing has shown that ~50% of cases of OS have a translocation involving the TP53 gene with breakpoints confined to the first intron. We developed a 2 color break-apart fluorescent in situ hybridization (FISH) probe for intron 1 of TP53 and applied it to an archived series to assess its diagnostic utility. The study group included 37 cases of OS (including osteoblastic, chondroblastic, and fibroblastic), as well as 53 cases of non-OS pediatric sarcomas (including Ewing sarcoma, rhabdomyosarcoma, undifferentiated small cell sarcoma, CCNB3-BCOR sarcoma, CIC-DUX sarcoma, synovial sarcoma, and malignant peripheral nerve sheath tumor) and 27 cases of benign bone lesions (including osteoblastoma, chondromyxoid fibroma, fibrous dysplasia, and fibro-osseous dysplasia). A rearranged signal was found in 20/37 cases (54%) of OS and in none of the other sarcomas or benign bone lesions, giving the FISH test 100% specificity for a diagnosis of OS. p53 immunostaining was generally not predictive of the results obtained by FISH and could not substitute for this test. This FISH probe offers a simple and specific genetic test to aid in the diagnosis of OS, despite the genetic complexity of this tumor.

P53 and p16 immunostaining patterns in squamous cell carcinoma of the vulva predicts disease recurrence and prognosis

P53 and p16 immunostaining patterns in squamous cell carcinoma of the vulva predicts disease recurrence and prognosis

Stromal p16 Overexpression in Gastric-type Mucinous Carcinoma of the Uterine Cervix.

Gastric-type mucinous carcinoma (MC-G) of the uterine cervix displays distinct morphological features and an aggressive clinical course. The expression status of p16 in the stroma has not been investigated in adenocarcinoma of the uterine cervix. Stromal p16 expression was evaluated in endocervical adenocarcinomas, including usual-type endocervical adenocarcinoma (UEA), intestinal-type mucinous carcinoma (MC-I), and MC-G. Whether stromal p16 expression varied significantly according to the histological subtype and whether the expression status is associated with clinicopathological characteristics of MC-G was also investigated. Immunostaining of p16 was performed for 24, 19, and 18 cases of UEA, MC-I, and MC-G, respectively. UEA and MC-I subtypes exhibited horizontally continuous, strong nuclear p16 immunoreactivity in the tumor cells, whereas none of the MC-G cases showed diffuse and strong nuclear immunoreactivity for p16 in the tumor cells. Instead, 10 (55.6%) cases of MC-G displayed moderately to strongly positive p16 expression in the stroma. Stromal p16 expression of MC-G was significantly higher than that of normal cervix, UEA, and MC-I. Metastatic MC-G had significantly higher stromal p16 expression than primary MC-G. Further, stromal p16 overexpression in MC-G was associated with advanced stage, parametrial invasion, and lymphovascular invasion. Stromal p16 expression of MC-G was significantly higher than that of normal cervix and other histological subtypes of adenocarcinoma and was associated with advanced stage, parametrial invasion, and lymphovascular invasion, reflecting the aggressive behavior of MC-G. Our observations suggest that stromal p16 expression is involved in the development and progression of MC-G.

Preantral follicular atresia occurs mainly through autophagy, while antral follicles degenerate mostly through apoptosis.

There is a general agreement that granulosa cell apoptosis is the cause of antral follicle attrition. Less clear is whether this pathway is also activated in case of preantral follicle degeneration, as several reports mention that the incidence of granulosa cell apoptosis in preantral follicles is negligible. Our objective is therefore to determine which cell-death pathways are involved in preantral and antral follicular degeneration.Atretic preantal and antral follicles were investigated using immunohistochemistry and laser-capture microdissection followed by quantitative real-time reverse transcription polymerase chain reaction. Microtubule-associated light-chain protein 3 (LC3), sequestosome 1 (SQSTM1/P62), Beclin1, autophagy-related protein 7 (ATG7), and cleaved caspase 3 (cCASP3) were used as markers for autophagy and apoptosis, respectively. P62 immunostaining was far less intense in granulosa cells of atretic compared to healthy preantral follicles, while no difference in LC3 and BECLIN1 immunostaining intensity was observed. This difference in P62 immunostaining was not observed in atretic antral follicles. mRNA levels of LC3 and P62 were not different between healthy and atretic (pre)antral follicles. ATG7 immunostaining was observed in granulosa cells of preantral atretic follicles, not in granulosa cells of degenerating antral follicles. The number of cCASP3-positive cells was negligible in preantral atretic follicles, while numerous in atretic antral follicles. Taken together, we conclude that preantral and antral follicular atresia is the result of activation of different cell-death pathways as antral follicular degeneration is initiated by massive granulosa cell apoptosis, while preantral follicular atresia occurs mainly via enhanced granulosa cell autophagy.

Evaluation of the eighth TNM classification on p16-positive oropharyngeal squamous cell carcinomas in the Netherlands and the importance of additional HPV DNA testing

BackgroundOropharyngeal squamous cell carcinomas (OPSCCs) are traditionally caused by smoking and excessive alcohol consumption. However, in the last decades high-risk human papillomavirus (HPV) infections play an increasingly important role in tumorigenesis. HPV-driven OPSCCs are known to have a more favorable prognosis, which has led to important and marked changes in the recently released TNM-8. In this 8th edition, OPSCCs are divided based on p16 immunostaining, with p16 overexpression as surrogate marker for the presence of HPV. The aims of this study are to evaluate TNM-8 on a Dutch consecutive cohort of patients with p16-positive OPSCC and to determine the relevance of additional HPV DNA testing. Patients and methodsAll OPSCC patients without distant metastases at diagnosis and treated with curative intent at VU University Medical Center (2000–2015) and Erasmus Medical Center (2000–2006) were included (N=1204). HPV status was determined by p16 immunostaining followed by HPV DNA PCR on the p16-immunopositive cases. We compared TNM-7 and TNM-8 using the Harrell’s C index. ResultsIn total, 388 of 1204 (32.2%) patients were p16-immunopositive. In these patients, TNM-8 had a markedly better predictive prognostic power than TNM-7 (Harrell’s C index 0.63 versus 0.53). Of the 388 p16-positive OPSCCs, 48 tumors (12.4%) were HPV DNA-negative. This subgroup had distinct demographic, clinical and morphologic characteristics and showed a significantly worse five-year overall survival compared with the HPV DNA-positive tumors (P<0.001). ConclusionsTNM-8 has a better predictive prognostic power than TNM-7 in patients with p16-positive OPSCC. However, within p16-positive OPSCCs, there is an HPV DNA-negative subgroup with distinct features and a worse overall survival, indicating the importance to perform additional HPV DNA testing when predicting prognosis and particularly for selecting patients for de-intensified treatment regimens.

Tu1127 - The Risk of Neoplastic Progression Associated with Aberrant Immunostaining for P53 in Barrett's Esophagus: Systematic Review and Meta-Analysis

Tu1127 - The Risk of Neoplastic Progression Associated with Aberrant Immunostaining for P53 in Barrett's Esophagus: Systematic Review and Meta-Analysis

Evaluation of the efficacy of the 4 tests (p16 immunochemistry, polymerase chain reaction, DNA, and RNA in situ hybridization) to evaluate a human papillomavirus infection in head and neck cancers: a cohort of 348 French squamous cell carcinomas

It is now established that human papillomavirus (HPV) plays a role in the development of a subset of head and neck squamous cell carcinomas (SCCs), notably oropharyngeal (OP) SCCs. However, it is not clear which test one should use to detect HPV in OP and non-OP SCCs. In this study, using 348 head and neck SCCs (126 OP SCCs and 222 non-OP SCCs), we evaluated diagnostic performances of different HPV tests in OP and non-OP SCCs: polymerase chain reaction, p16 immunostaining, in situ hybridization targeting DNA (DNA-CISH) and RNA (RNA-CISH), combined p16 + DNA-CISH, and combined p16 + RNA-CISH. HPV DNA (polymerase chain reaction) was detected in 26% of all tumors (44% of OP SCCs and 17% of non-OP SCCs). For OP SCCs, RNA-CISH was the most sensitive stand-alone test (88%), but p16 + RNA-CISH was even more sensitive (95%). Specificities were the same for RNA-CISH and DNA-CISH (97%), but it was better for p16 + RNA-CISH (100%). For non-OP SCCs, all tests had sensitivities less than 50%, and RNA-CISH, DNA-CISH, and p16 + DNA-CISH had 100%, 97%, and 99% specificities, respectively. As a stand-alone test, RNA-CISH is the most performant assay to detect HPV in OP SCCs, and combined p16 + RNA-CISH test slightly improves its performances. However, RNA-CISH has the advantage of being one single test. Like p16 and DNA-CISH, RNA-CISH performances are poor in non-OP SCCs to detect HPV, and combining tests does not improve performances.

Expression and Clinical Implication of Autophagy-Associated Protein p62 in Osteosarcoma

Purpose: Recent studies highlight the role of autophagy in cancer tumorigenesis, recurrence, metastasis, and chemoresistance. p62 is an adapter protein that is crucial for the autophagy pathway. In this study, we will describe the expression of p62 and its correlation with clinic prognosis in osteosarcoma. Methods: Western blot was used to test the expression of p62 in osteosarcoma cell lines (U2OS, KHOS, MG63, Saos-2, U2OSR2, KHOSR2, and 143B). A tissue microarray (TMA) was analyzed by immunohistochemistry to determine the expression levels of p62 in osteosarcoma patients and evaluate any correlation between p62 and clinical characteristics in osteosarcoma patients. Results: p62 was expressed differently in all cell lines. The TMA also showed differential expression in osteosarcoma tissues. Seventy-five of 79 (94.9%) patient tissues exhibited p62 immunostaining, ranging from no staining (4 of 97, 5.1%) to 1+ staining (40 of 79, 50.6%), 2+ staining (17 of 79, 21.5%), and 3+ staining (18 of 79, 22.8%). The low staining (1+) was classified as the p62 weak group (50.6%), the medium staining (2+) and intense staining (3+) were classified as the p62 strong group (44.3%). Analyzing the clinical data of the osteosarcoma TMA, we found that the 5-year survival rate of patients with weak p62 expression was significantly lower than that of the patients with strong p62 expression (p = 0.0165). Furthermore, the decreased p62 expression may be associated with higher metastatic and chemoresistant rates in osteosarcoma patients. Conclusion: Our results suggest that p62 may be an effective predictor of prognosis and a potential target for therapy in osteosarcoma.

Staging of oropharyngeal carcinomas : New TNM classification as achallenge for head and neck cancer centers

The TNM (tumor, nodes, metastasis) classification is updated periodically according to the literature and international recommendations. With the 8th edition, notable changes have been developed especially with regard to oropharyngeal cancer. The modifications as well as the practicability of the classification for staging of oropharyngeal cancers are demonstrated on the basis of cases from the tumor database. The latest edition of the TNM classification realizes requirements to differentiate between human papilloma virus (HPV) positive and HPV-negative tumors during staging. Furthermore, the prognostic relevance of extranodal extension of lymph node metastases was integrated into the classification. While downstaging is performed regarding Ncategory and Union Internationale Contre le Cancer (UICC) stage in many p16-positive tumors, for p16-negative tumors, extranodal spread mostly leads to anotable upstaging. Due to limited specificity of the p16 immunostaining, the relevance of false positive results has to be underlined. Missing integration of smoking behavior, limited standardization of the extranodal extension examination technique, as well as high demands on the documentation quality should be kept in mind. Clinical trials will have to show whether deescalation strategies regarding p16-positive carcinomas are supported by the changes made in the TNM staging system. Aprospective multicenter study should examine the universal applicability, the appropriateness for all sublocations, as well as the prognostic significance of the current edition.

Clinicopathological Characteristics of High-grade Squamous Intraepithelial Lesions Involving Condyloma Acuminatum.

Severe nuclear atypia can be associated with condyloma acuminatum. In this study, we investigated nine cases of perianal condyloma acuminatum with severe nuclear atypia and determined whether severe nuclear atypia is sufficient for the diagnosis of high-grade squamous intraepithelial lesion (HSIL). The clinical data and pathological features of the nine patients were collected. p16 Immunostaining and human papillomavirus genotyping were also performed. The resected specimens of six men infected with human immunodeficiency virus showed features suggestive of HSIL, including the expansion of basaloid cells, severe nuclear pleomorphism in the lower one-third, bizarre nuclei, mitotic figure in the upper two-thirds, atypical mitosis, block positivity for p16, and high-risk human papillomavirus infection. In contrast, the resected specimens of the remaining three patients did not show any of those HSIL features, even though there were several microscopic foci showing severe nuclear atypia in the upper two-thirds of the papillomatous epithelium. Our observation regarding the occurrence of HSIL involving perianal condyloma acuminatum in human immunodeficiency virus-infected patients suggests that active, complete surgical excision of perianal condyloma acuminatum and a thorough histopathological examination are necessary. The diagnosis of severe nuclear atypia involving the upper two-thirds of the epithelium should be made with great caution.

Diagnostic Challenge of Cervical Intraepithelial Neoplasia with Concurrent Follicular Cervicitis: Histomorphological Features and P16 Immunostaining as a Diagnostic Adjunct

Diagnostic Challenge of Cervical Intraepithelial Neoplasia with Concurrent Follicular Cervicitis: Histomorphological Features and P16 Immunostaining as a Diagnostic Adjunct

Profile of p53 expression in epithelial ovarian carcinomas: A multicenter study from South-East Nigeria

Background: Therapeutic targeting of mutated protein 53 (p53) will require the knowledge of mutated p53 expression. Currently, there is paucity of data on the expression of p53 in epithelial ovarian cancer (EOC) in Nigeria. Objective: This study therefore aims to carry out an immunohistochemical study of histologically diagnosed EOCs in Nnewi, South-East Nigeria. Materials and Methods: Hematoxylin and eosin slides and paraffin blocks of all histologically diagnosed cases of epithelial ovarian carcinomas in the two histopathology laboratories in Nnewi, Anambra State, over a 7-year period, were retrieved from the archives. Archival paraffin blocks of histologically normal ovaries in these laboratories were also retrieved to serve as controls. Sections were made from the tissue blocks and stained with p53 immunostain. Results: Fifty EOC specimen and twenty histologically normal ovaries were enrolled in this study. While 58% of EOC showed p53 positivity, none of the histologically normal ovaries showed p53 positivity. p53 expression was more common in those above 50 years of age, yet no association was found between p53 expression and age of patient. However, there was a statistically significant association between p53 positivity and tumor grade (P

Expression of cell cycle inhibitors in canine prostate with proliferative inflammatory atrophy and carcinoma

ABSTRACT Gene expression of CDKN1A, CDKN1B, and TP53, and immunostaining of p21, p27 and p53 were evaluated to verify the role of these cell cycle inhibitors in canine prostates with proliferative inflammatory atrophy-PIA and prostatic carcinoma-PC. Seventy samples, 15 normal, 30PIA and 25PC. Regarding number of p27 and p53 labeled cells, difference between normal and PIA and PC was observed, as well as between PIA and PC for p53. Immunostaining intensities of p21, p27 and p53 were different when comparing normal tissues to PIA and PC. Sixteen cDNA of canine prostatic FFPE tissue were subjected to RT-PCR and RT-qPCR, four normal, three PIA, and nine PC. CDKN1A mRNA was detected in four PC by RT-PCR, and it was overexpressed when compared to normal by RT-qPCR, in one PIA and six PC. CDKN1B mRNA was detected in three PC by RT-PCR and it was overexpressed in three PC and decreased in one PC. TP53 mRNA was overexpressed in one PIA and three PC. In conclusion, when overexpressed in canine prostate with premalignant and malignant, p21 and p27 play a role controlling cell proliferation, working as a protective factor in the evolution of PIA to PC, and in the PC development, even in the presence of altered p53.

Study of Keratinocyte Proliferation, Apoptosis and Dermal Inflammation in Psoriatic Skin Lesions Before and After Methotrexate Therapy: Which Change Is Contributing More to Clinical Severity of the Disease?

Objective: The pathogenesis of psoriasis involves T-cell mediated immunologic response, keratinocytes hyperproliferation, and resistance to apoptosis. Methotrexate is one of the most reliable modalities in the treatment of psoriasis that target those changes. The study of those variables before and after methotrexate therapy may answer the question: Which of those variables contributes more to the clinical severity of the disease and is more valuable to be targeted in psoriasis treatment. Patients and Methods: A total of 50 cases of psoriasis vulgaris were included, 25 patients received methotrexate therapy. Skin biopsies of psoriatic skin lesions before and after treatment were examined histologically for measurement of epidermal thickness and grading of dermal inflammation. Immunostaining for Ki-67 and p53 was done for assessment of keratinocyte proliferation and apoptosis. Results were correlated with clinical severity of the disease, assessed by psoriatic area and severity index (PASI) score. 15 biopsies of normal skin were included as control. Results: Dermal inflammation, Ki-67%, and p53% were significantly higher in psoriatic skin lesion than in normal skin. Those changes were significantly correlated with PASI score. Multiple logistic regression models revealed that Ki-67 was the most significant variable contributing to clinical severity. One unit change in ki-67% can explain 1.2 unit changes in PASI score with 97% sensitivity, 40% specificity and 25% cut-off value. PASI score, dermal inflammation, Ki-67% and P53% were significantly reduced after methotrexate therapy. No significant difference was detected between the percent reduction in PASI score (81%) and that of Ki-67% (70%). Conclusion: Keratinocyte proliferation was the most significant variable contributing to the clinical severity of psoriasis and it was the single parameter that showed parallel changes to PASI score after methotrexate therapy. Keratinocyte proliferation may be considered as the stimulus that induces all other pathological and clinical changes in psoriasis and should be targeted by therapy.

Usefulness of p16 Immunostaining in the Diagnosis of Bowenoid Papulosis

Usefulness of p16 Immunostaining in the Diagnosis of Bowenoid Papulosis

Breast Adenomyoepithelioma with predominance of morules: a cytological dilemma.

Adenomyoepithelioma is a rare, benign proliferative tumour that can involve the breast. It is usually present as a solitary, unilateral, painless mass at the periphery of the breast in women range in age from 26 to 82 years (average 63 years). Tumour sizes range from 0.5 to 8 cm. (average size 2.5 cm).We report a case of adenomyoepithelioma of right breast in a 58 years old female since two months with diagnostic difficulty on cytology, especially with morules predominance that merits documentation due to its rarity. On physical examination, it was a single well defined, lobulated, non mobile, firm mass of 10 x 8 x 5 cm in upper outer quadrant of right breast without associated axillary lymphadenopathy. Sonomammography showed well defined lobulated right breast mass with macrolobulations and cystic changes suggestive of phyllodes tumour. Wide local excision was performed and histopathological study revealed adenomyoepithelioma which is confirmed by P63 immunostain. DOI: 10.21276/APALM.1311

TP53 Mutation Status of Tubo-ovarian and Peritoneal High-grade Serous Carcinoma with a Wild-type p53 Immunostaining Pattern.

Diffuse and strong nuclear p53 immunoreactivity and a complete lack of p53 expression are regarded as indicative of missense and nonsense mutations, respectively, of the TP53 gene. Tubo-ovarian and peritoneal high-grade serous carcinoma (HGSC) is characterized by aberrant p53 expression induced by a TP53 mutation. However, our experience with some HGSC cases with a wild-type p53 immunostaining pattern led us to comprehensively review previous cases and investigate the TP53 mutational status of the exceptional cases. We analyzed the immunophenotype of 153 cases of HGSC and performed TP53 gene sequencing analysis in those with a wild-type p53 immunostaining pattern. Immunostaining revealed that 109 (71.3%) cases displayed diffuse and strong p53 expression (missense mutation pattern), while 39 (25.5%) had no p53 expression (nonsense mutation pattern). The remaining five cases of HGSC showed a wild-type p53 immunostaining pattern. Direct sequencing analysis revealed that three of these cases harbored nonsense TP53 mutations and two had novel splice site deletions. TP53 mutation is almost invariably present in HGSC, and p53 immunostaining can be used as a surrogate marker of TP53 mutation. In cases with a wild-type p53 immunostaining pattern, direct sequencing for TP53 mutational status can be helpful to confirm the presence of a TP53 mutation.

A Selected Immunohistochemical Panel Aids in Differential Diagnosis and Prognostic Stratification of Subtypes of High-grade Endometrial Carcinoma: A Clinicopathologic and Immunohistochemical Study at a Single Institution.

This study aimed to investigate whether a selected immunohistochemical panel (estrogen receptor, p53, ARID1A, PPP2R1A, HNF-1β) could contribute to the diagnostic process of high-grade endometrial carcinomas (HG-ECs). We also aimed to analyze the correlation of these immunohistochemical results with several morphologic variables and survival data. After revising the diagnosis of 78 HG-ECs, immunohistochemical analysis was performed for each case. After immunohistochemical analysis, a specific diagnosis of prototypic HG-EC was established in most of the cases that were uncertain due to morphologic ambiguity. In the univariate analysis, older patient age, type II morphology, undifferentiated carcinoma and carcinosarcoma type of histology, altered p53 immunostaining, strong membranous staining of PPP2R1A, presence of lymphovascular invasion in serous carcinoma, and microcystic, elongated, and fragmented-type infiltration pattern in endometrioid carcinoma were significantly related to poor prognosis. In the multivariate analysis, only older patient age and carcinosarcoma or undifferentiated/dedifferentiated carcinoma type histology were found to be significantly poor prognostic factors (P=0.011), whereas advanced FIGO stage and type II histology were found to be correlated with poor prognosis, but did not reach statistical significance. We suggest that immunohistochemistry should be used in the differential diagnosis of HG-ECs, especially those with ambiguous morphology. Markers used in this study made a valuable contribution to the diagnostic process as well as prediction of prognosis.