Stratified mucin-producing intraepithelial lesions of the cervix: adenosquamous or columnar cell neoplasia?

Invasive stratified mucin-producing carcinoma (ISMC) of the cervix: a clinicopathological and molecular analysis of 59 cases with special emphasis on histogenesis and potential therapeutic targets

AIMS

This study aimed to better characterize the clinical and molecular features in invasive stratified mucin-producing carcinoma (ISMC), an uncommon aggressive subtype of endocervical adenocarcinoma (EAC).

METHODS AND RESULTS

We recruited 59 ISMC for clinicopathological analysis, immunohistochemistry (n = 56), and targeted next-generation sequencing (n = 17). Our cases contained 29 pure and 30 mixed-type ISMC. Five patients developed local recurrence at 6-32 months (median: 13 months), and died of disease at 16-55 months (median: 16 months). Pure and mixed-type ISMC showed no significant difference in overall survival and tumour relapse (P > 0.05) except larger tumour size in the pure-type (P = 0.009). Compared to the usual-type EAC (n = 217), ISMsC were more frequently associated with large tumour size (P = 0.003), advanced FIGO stage (P = 0.017), lymph node metastasis (P = 0.022), Silva pattern C (P < 0.001), and poor overall survival and short tumour recurrence. SOX2 expression was observed in 82.1% (46/56) ISMC, substantially higher than p63 expression (P < 0.001), while positive SOX17 was present in 3.6% (2/56) cases. PD-L1 was positive in 41/56 ISMC (73.21%) (combined positive score: range: 1-92, median: 22). Three ISMC patients (17.65%) had PIK3CA mutations, while one each (5.88%) patient harboured an ERBB2, TP53, STK11, and PTEN mutation, respectively.

CONCLUSION

We conclude that ISMC is clinically more aggressive than the usual-type EAC. ISMC may originate from cervical reserve cells with bidirectional differentiation. PD-L1 overexpression and the molecular profiles raise the possibility that a subset of ISMC patients may benefit from anti-PD-L1 immunotherapy and other targeted therapy, such as mTOR inhibitor and T-DM1.

Invasive Squamous Cell Carcinoma of the Cervix: A Review of Morphological Appearances Encountered in Human Papillomavirus-associated and Papillomavirus-independent Tumors and Precursor Lesions

Cervical cancer is the fourth most common cancer among women globally. Historically, human papillomavirus (HPV) infection was considered necessary for the development of both precursor and invasive epithelial tumors of the cervix; however, studies in the last decade have shown that a significant proportion of cervical carcinomas are HPV-independent (HPVI). The 2020 World Health Organization (WHO) Classification of Female Genital Tumors separates both squamous cell carcinomas (SCCs) and endocervical adenocarcinomas (ECAs) by HPV status into HPV-associated (HPVA) and HPVI tumors. The classification further indicates that, in contrast to endocervical adenocarcinomas, HPVI and HPVA SCCs cannot be distinguished by morphological criteria alone and suggests that HPV testing or correlates thereof are required for correct classification. Moreover, while HPVA SCC precursor lesions (ie, high-grade squamous intraepithelial lesion) are well known and characterized, precursors to HPVI SCCs have only been described recently in a small number of cases. We studied 670 cases of SCCs from the International Squamous Cell Carcinoma Project (ISCCP) to analyze the reproducibility of recognition of invasive SCC growth patterns, presence of lymphovascular space invasion, tumor grade, and associations with patient outcomes. Consistent with previous studies, we found histologic growth patterns and tumor types had limited prognostic implications. In addition, we describe the wide morphologic spectrum of HPVA and HPVI SCCs and their precursor lesions, including tumor growth patterns, particular and peculiar morphologic features that can lead to differential diagnoses, and the role of ancillary studies in the diagnosis of these tumors.

TP53 Mutation-driven Stratified Mucin-producing Carcinoma Coexisting With Squamous Cell Carcinoma of the Vulva: A Case Study

Associated with high-risk human papillomavirus infection, invasive stratified mucin-producing carcinoma is a recently characterized adenocarcinoma of the cervix. It often occurs in association with adjacent stratified mucin-producing intraepithelial lesion. Differentiated vulvar intraepithelial neoplasia and related invasive squamous cell carcinoma often arise in background vulvar lichen sclerosus with TP53 mutation as the underlying molecular signature. We present a unique case of vulvar invasive stratified mucin-producing carcinoma-like component coexisting with invasive squamous cell carcinoma in a 64-year-old woman. Both neoplastic components were proven TP53 -driven processes arising in the background of differentiated vulvar intraepithelial neoplasia and lichen sclerosus. The invasive stratified mucin-producing carcinoma-like component behaved aggressively in this case, evidenced by the presence of lymphovascular invasion and inguinal lymph node metastasis.

Pleural fluid cytology of metastatic invasive stratified mucin-producing carcinoma from the cervix: A case report

This study analyses the cytomorphological findings from a female patient with malignant pleural effusion resulting from invasive stratified mucin‐producing carcinoma (ISMC) metastasis. The clinical symptoms, immunocytochemical staining and differential diagnosis of ISMC are summarised.

Cervical Adenosquamous Carcinoma: Detailed Analysis of Morphology, Immunohistochemical Profile, and Outcome in 59 Cases

Although both the 2014 and 2020 World Health Organization (WHO) criteria require unequivocal glandular and squamous differentiation for a diagnosis of cervical adenosquamous carcinoma (ASC), in practice, ASC diagnoses are often made in tumors that lack unequivocal squamous and/or glandular differentiation. Considering the ambiguous etiologic, morphologic, and clinical features and outcomes associated with ASCs, we sought to redefine these tumors. We reviewed slides from 59 initially diagnosed ASCs (including glassy cell carcinoma and related lesions) to confirm an ASC diagnosis only in the presence of unequivocal malignant glandular and squamous differentiation. Select cases underwent immunohistochemical profiling as well as human papillomavirus (HPV) testing by in situ hybridization. Of the 59 cases originally classified as ASCs, 34 retained their ASC diagnosis, 9 were reclassified as pure invasive stratified mucin-producing carcinomas, 10 as invasive stratified mucin-producing carcinomas with other components (such as HPV-associated mucinous, usual-type, or ASCs), and 4 as HPV-associated usual or mucinous adenocarcinomas with benign-appearing squamous metaplasia. Two glassy adenocarcinomas were reclassified as poorly differentiated HPV-associated carcinomas based on morphology and immunophenotype. There were no significant immunophenotypic differences between ASCs and pure invasive stratified mucin-producing carcinomas with regard to HPV and other markers including p16 expression. Although limited by a small sample size, survival outcomes seemed to be similar between all groups. ASCs should be diagnosed only in the presence of unequivocal malignant glandular and squamous differentiation. The 2 putative glassy cell carcinomas studied did not meet our criteria for ASC and categorizing them as such should be reconsidered.

Adenosquamous carcinoma in situ of the anus: a case series

While human papillomavirus (HPV)-associated adenocarcinoma of the anus resembling endocervical adenocarcinoma has recently been described, anal adenocarcinoma in situ/AIS has not. Moreover, to the best of our knowledge, truly biphasic anal adenosquamous carcinoma in situ (ADSQ-IS) is essentially non-existent in the literature. Here, we report four cases of anal ADSQ-IS including one with associated invasive adenosquamous carcinoma. Histologically, all cases of ADSQ-IS showed a basal/peripheral population of stratified, p40-positive dysplastic squamous cells adjacent to luminal, columnar, p40-negative dysplastic glandular cells, bearing a striking resemblance to the normal anal transitional epithelium. Both lesional components were diffusely and strongly positive for p16 and positive for high-risk HPV by RNA in situ hybridization. These cases expand the morphological spectrum of high-risk HPV-associated pre-invasive lesions and underscore the plasticity of HPV-associated neoplasia.

Comprehensive profile and contrastive analysis of circular RNA expression in cervical squamous carcinoma and adenocarcinoma

Background

Numerous studies have shown circular RNA (circRNA) dysregulation is associated with the pathogenesis of cervical cancer,particularly in individual carcinoma variants. The aim of this study is to investigate and contrastively analyze the expression pattern of circRNAs in cervical squamous carcinoma and adenocarcinoma mediated by human papillomavirus type 16 (HPV-16).

Methods

The expression of circRNAs in cervical squamous carcinoma (SCC), adenocarcinoma (ADC) and adenosquamous carcinoma (ASC) tissues, together with the adjacent normal tissues (ANT), was profiled by high-throughput RNA sequencing (RNA-seq). Bioinformatics analysis and quantitative real time polymerase chain reaction (qRT-PCR) validation of the sequencing data were performed. A network of circRNA-miRNA (microRNA)-mRNA was then constructed according to predicted targets and function of candidate circRNAs.

Results

A total of 11,685 annotated circRNAs were identified in six cervical samples. There were 42 up-regulated and 98 down-regulated circRNAs. 215 circRNAs were up-regulated in SCC but down-regulated circRNAs in ADC, while 50 circRNAs displayed the opposite trend. Function enrichment analysis based on different expressions of circRNAs found that the most enriched pathway in all the three pathologic variants of cervical cancer was the "ubiquitin mediated proteolysis" pathway. Eight key candidate circRNAs derived from this pathway were further validated, and we noticed that several target miRNAs of candidate circRNAs could target the source genes. Based on this we constructed a related competing endogenous RNA (ceRNA) network.

Conclusion

Through a comprehensive interpretation of differentially expressed circRNAs in different pathologic variants of cervical cancer, this study provides new insights into the process of tumor differentiation mediated by HPV. Our results may help to complement the molecular typing and stem cell theory of cervical cancer.

Dataset for the Reporting of Carcinoma of the Cervix: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

Cervical carcinoma remains one of the most common cancers affecting women worldwide, despite effective screening programs being implemented in many countries for several decades. The International Collaboration on Cancer Reporting (ICCR) dataset for cervical carcinoma was first developed in 2017 with the aim of developing evidence-based standardized, consistent and comprehensive surgical pathology reports for resection specimens. This 4th edition update to the ICCR dataset on cervical cancer was undertaken to incorporate major changes based upon the updated International Federation of Obstetricians and Gynecologists (FIGO) staging for carcinoma of the cervix published in 2018 and the 5th Edition World Health Organization (WHO) Classification of Female Genital Tumors published in 2020 and other significant developments in pathologic aspects of cervical cancer. This updated dataset was developed by a panel of expert gynecological pathologists and an expert gynecological oncologist, with a period of open consultation. The revised dataset includes "core" and "noncore" elements to be reported; these are accompanied by detailed explanatory notes and references providing the rationale for the updates. Standardized reporting using datasets such as this helps facilitate consistency and accuracy, data collection across different sites and comparison of epidemiological and pathologic parameters for quality and research purposes.

Benign stratified intraepithelial mucinous proliferation of the uterine cervix: Significance of a previously unreported potential mimic of SMILE

Stratified mucin-producing intraepithelial lesion (SMILE) is a histologic subtype of HPV-associated endocervical adenocarcinoma in situ. We have observed benign endocervical changes resembling SMILE. We aim to characterize this pattern and explore its potential association with dysplasia. We retrospectively retrieved all 296 consecutive cases accessioned as endocervical biopsies. Some included multiple specimens, totaling 483 biopsies and 219 endocervical curettages (ECC), n = 702. We included cases showing endocervical epithelial stratification often with pencillate (triangular-shaped) nuclei. We rejected cases in which layering represented tangential sectioning, metaplasia, microglandular hyperplasia, gastric type epithelial changes, and dysplasia. We found benign stratified intraepithelial mucinous proliferation in 51 patients, either with a multilayered (n = 27) or a two-layered appearance (n = 24). Overall, multilayered proliferation occurred in 6 % (29/483) of biopsies and in 0.9 % of ECCs (2/219). Two-layering was identified in 4 % of all biopsies (20/482) and was not seen in ECCs. Histologic findings included stratification, intracytoplasmic mucin, paler cytoplasm, low nuclear-to-cytoplasmic ratio, often pencillate nuclei, rare mitoses, and no apoptotic bodies. P16 immunohistochemistry (n = 12) was negative, suggesting absence of underlying high-risk HPV infection. HSIL was concomitant in 29.6 % (8/27) of patients with multilayered proliferation. Concurrent SMILE was not observed. We also reviewed 13 SMILE cases. Concurrent multilayered benign proliferation was identified in 54 % (7/13) of cases. We describe benign stratified intraepithelial mucinous proliferation of the cervix, which morphologically may overlap with SMILE. Its presence in most SMILE cases suggests a potential relationship. The multilayered form represents a diagnostic pitfall when mitotically active. Because of the often-coexistent HSIL, we propose that its presence should prompt scrutiny to rule out any associated dysplasia.

Invasive stratified mucin-producing carcinoma (ISMC) of uterine cervix: description of pathological findings and prognosis factors in a series of 15 Chinese patients

PURPOSE

Invasive stratified mucin-producing carcinoma (ISMC), an invasive form of stratified mucin-producing intraepithelial lesion (SMILE), is a newly named human papillomavirus (HPV) associated mucous adenocarcinoma of cervix. We aim to provide more clinical and pathological data for this uncommon disease.

METHODS

Fifteen cases diagnosed as ISMC in our hospital were included, and their clinical and pathological data were retrospectively analyzed.

RESULTS

The patients' median age was 43 years (range, 30-54 years). The most prevalent symptom was abnormal vaginal bleeding. HPV test indicated high-risk HPV in all of our 15 cases. In addition, we observed several other architectural patterns of ISMC, including nest, gland-forming or lumen-forming, papillary with extravasated pools of mucin and solid. Immunohistochemically, all of our ISMC cases showed block-like expression of P16 and diffuse positive expression of CK8 and CK18, while P63, P40 and CK5/6 were spotted positive, or completely negative. Most importantly, ISMC has a relatively high lymph node metastasis rate of 33%.

CONCLUSIONS

ISMC is a special type of HPV-associated adenocarcinoma, displaying a wide morphologic spectrum combined with a unique immunohistochemical profile. Clinically, ISMC may have a higher rate of lymph node metastasis, which suggests more attention to postoperative follow-up.

Independent validation of distinct clinicopathological features and prognosis among usual-type, mucinous-type and gastric-type endocervical adenocarcinoma categorised by new WHO classification (2020)

The new World Health Organization (WHO) classification of tumours of the female genital tract (2020) divides endocervical adenocarcinoma (EAC) into human papilloma virus (HPV)-related adenocarcinoma (HPVA) and HPV-independent adenocarcinoma (HPVI) to underscore the morphological and pathogenetic correlation. It may be potentially prognostic. In this study, we appraised the new WHO classification in an independent, single institution-based EAC cohort from China to assess the clinicopathological features and prognostic value among tumour types. Our study cohort contained 402 consecutive, surgically excised EACs consisting of 298 (74.1%) HPVA, 88 (21.9%) HPVI and 16 (4%) adenocarcinomas not otherwise specified (NOS). Usual-type (55.7%) and gastric-type adenocarcinoma (GAC) (18.2%) was the most common type in HPVA and HPVI, respectively. Block p16 staining (94.7% vs 24.4%) and HPV mRNA signal (89.4% vs 0) were more common in HPVA than in HPVI (p<0.001). HPVI or GAC were more frequently associated with prognostically adverse variables including old age, large tumour size, deep invasion of the cervical wall, high tumour stage, spread of the upper genital tract, lymphovascular invasion, and mutant-type p53 expression, compared to HPVA or mucinous/usual-type HPVA, respectively (all p<0.001). In univariate survival analysis, HPVI had a worse overall survival and higher tumour recurrence compared to HPVA (p<0.05). Mucinous-type HPVA showed a worse prognosis than usual-type HPVA, but better than GAC (p<0.001). Multivariate survival analysis demonstrated that HPVI was independently associated with a worse overall survival and tumour recurrence (p<0.05) while GAC was an adverse prognostic factor independently of FIGO stage (p<0.05). Our findings validate the value of the new WHO classification in prognostic stratification and pathogenetic correlation in EAC and its subtypes.

Key changes to the world health organisation (who) classification of female genital tumours introduced in the 5TH edition (2020)

An updated World Health Organisation (WHO) Classification of Female Genital Tumours was published in Autumn 2020. We discuss the major new additions and changes from the prior 2014 Classification with discussion of the reasons underlying these. A feature of the new Classification is the greater emphasis on key molecular events with integration of morphological and-molecular features. Most of the major changes from the prior Classification pertain to uterine (corpus and cervix) and vulval tumours but changes in all organs are covered.

HPV-driven anal neoplasia: review and recent developments

A host of human papillomavirus (HPV)-associated squamous and glandular lesions may be identified in the anal canal in men and women. Given their relative rarity, familiarity with the morphological spectrum associated with HPV-driven anal neoplasia is important for proper identification and diagnosis. In this article, we review the classification and basic histopathological features of HPV-related squamous intraepithelial and invasive lesions as well as associated pitfalls. In addition, we provide an update on recently described HPV-driven, non-squamous tumours. As our experience with these lesions evolves, we expect the histological spectrum to further expand, particularly as it relates to non-squamous HPV-driven neoplasia.

Invasive Stratified Mucin-producing Carcinoma (ISMC) of the Uterine Cervix: Clinicopathological and Molecular Characteristics With Special Emphasis on the First Description of Consistent Programmed Death-ligand 1 (PD-L1) Over-expression

BACKGROUND/AIM

Invasive stratified mucin-producing carcinoma (ISMC) of the uterine cervix has been reported to be more aggressive than other subtypes of endocervical adenocarcinoma. We investigated the clinicopathological and molecular characteristics of eight ISMCs.

PATIENTS AND METHODS

We reviewed the electronic medical records and pathology slides of eight patients with ISMC and conducted programmed death-ligand 1 (PD-L1) immunostaining and targeted sequencing.

RESULTS

The patients were between 31 and 54 years. Six tumors were pure ISMCs, and two showed co-existing squamous cell carcinoma and usual-type endocervical adenocarcinoma. Lymph node metastases were detected in three cases. Three patients developed distant metastases to the adnexa, lungs, inguinal lymph nodes, and small intestine. Two patients experienced disease progression, and three developed postoperative local recurrences. All tumors showed PD-L1 over-expression, with a mean combined positive score of 73.8 (range=30-100). One tumor harbored erb-b2 receptor tyrosine kinase 2 amplification.

CONCLUSION

ISMC of the uterine cervix exhibits a high risk of recurrence, metastasis, and resistance to chemoradiation therapy. PD-L1 over-expression was consistently observed in all ISMCs. This finding raises the possibility that patients with ISMC may benefit from PD-L1 immunotherapy.

Immunohistochemical and genetic characteristics of HPV-associated endocervical carcinoma with an invasive stratified mucin-producing carcinoma (ISMC) component

Invasive stratified mucin-producing carcinoma (ISMC) is a recently described entity of human papillomavirus (HPV)-associated endocervical adenocarcinoma with phenotypic plasticity and aggressive clinical behavior. To identify the cell of origin of ISMC, we investigated the immunohistochemical expression of cervical epithelial cell markers (CK7, PAX8, CK5/6, p63, and CK17), stemness markers (ALDH1 and Nanog), and epithelial-mesenchymal transition (EMT) markers (Snail, Twist, and E-cadherin) in 10 pure and mixed type ISMCs with at least 10% of ISMC component in the entire tumor, seven usual type endocervical adenocarcinomas (UEAs), and seven squamous cell carcinomas (SCCs). In addition, targeted sequencing was performed in 10 ISMCs. ISMC was significantly associated with larger tumor size (p = 0.011), more frequent lymphovascular invasion and lymph node metastasis (p < 0.001), higher FIGO stage (p = 0.022), and a tendency for worse clinical outcomes (p = 0.056) compared to other HPV-associated subtypes. ISMC showed negative or borderline positivity for PAX8, CK5/6, and p63, which were distinct from UEA and SCC (p < 0.01). Compared to UEA and SCC, ISMC showed higher expression for ALDH1 (p = 0.119 for UEA and p = 0.009 for SCC), Snail (p = 0.036), and Twist (p = 0.119), and tended to show decreased E-cadherin expression (p = 0.083). In next-generation sequencing analysis, ISMC exhibited frequent STK11, MET, FANCA, and PALB2 mutations compared to conventional cervical carcinomas, and genes related to EMT and stemness were frequently altered. EMT-prone and stemness characteristics and peripheral expression of reserve cell and EMT markers of ISMC suggest its cervical reserve cell origin. We recommend PAX8, CK5/6, and p63 as diagnostic triple biomarkers for ISMC. These findings highlight the distinct biological basis of ISMC.

Stratified Mucin-Producing Intraepithelial Lesion (SMILE) of the Uterine Cervix: High-Risk HPV Genotype Predominance and p40 Immunophenotype

Stratified mucin-producing intraepithelial lesion (SMILE) is a rare high-grade cervical precancerous lesion designated a variant of adenocarcinoma in situ (AIS) in the WHO classification. We aimed to determine HPV genotypes, immunohistochemical phenotype and mucin presence in SMILE. Between 2010 and 2018, SMILE was diagnosed in 34 out of 6958 (0.5%) cervical biopsies, in 23 patients. Twenty-six tissue samples from twenty-one patients were available for further analysis, including 13 with SMILE alone, 12 with SIL and/or AIS and one with HSIL, AIS and endocervical adenocarcinoma. HPV genotyping was performed using the Seegene Anyplex II HPV 28 assay. Of the 26 samples, a single HPV genotype was identified in the majority of cases (n = 22), including 12/13 SMILEs associated with SIL/AIS. All but one were high-risk HPV genotypes (23/24; 96.8%). We identified seven different HPV genotypes, the most common being HPV16 (n = 10; 43.5%), HPV18 (n = 8, 34.8%) and HPV 31 (n = 5, 21.7%). All SMILEs showed a strong positive reaction to p16, CK7, CK19 and high Ki67 expression comparable to adjacent HSIL and/or AIS if present. SMILE showed variable mucin presence and p40-positive squamous differentiation suggesting phenotypic diversity in cervical precancerous lesions infected by single HPV.

SMILE-like lesion in the anal canal

Stratified mucin-producing intraepithelial lesion (SMILE) is an intraepithelial lesion with overlapping features of the high-grade squamous intraepithelial lesion (HSIL) and adenocarcinoma in situ (AIS). Currently, it is well described in the cervix. We present a case showing similar SMILE-like lesions in the polypectomy specimen from the anal canal along with invasive adenocarcinoma components. This lesion showed an immuno-profile characteristic of a SMILE lesion described in the cervix, such as p63 negativity, high ki67 index, and nuclear positivity for p16. It might be arising from the Human papillomavirus prone transitional region of the anal canal as described in the cervix. However, we could not assure this association and etiological link due to insufficient material in the formalin-fixed paraffin-embedded block. Notwithstanding, we strongly suggest that the HPV is the main driver for this SMILE-like lesion similar to what is described in the cervix. To our knowledge, this is the first case report of a SMILE lesion in the anal canal. Further studies will be required to elucidate the underlying pathogenetic mechanism of SMILE-like lesions described in the anal canal.

Cervical Stratified Mucin-Producing Intraepithelial Lesion: A Systematic Review of Diagnosis and Management

OBJECTIVES

The aims of the study were to synthesize reported associations of stratified mucin-producing intraepithelial lesion (SMILE) of the cervix with other dysplasia lesions and immunohistochemical (IHC) stains, compare expected patterns of IHC staining to other lesions in the differential diagnosis, and assess follow-up pathology.

METHODS

This systematic review includes all case reports and case series of cervical lesions consistent with SMILE based on the histologic diagnosis described in the original case series. MEDLINE, EMBASE, and Cochrane Database were searched through June 2019. Immunohistochemical analysis, concurrent lesions, and pathology on follow-up were compiled for comparison. Weighted averages of concurrent lesions were calculated.

RESULTS

Nine case reports and case series were included, published between 2000 and 2019. Of 9 studies, 6 and 5 studies reported strong, diffuse staining of p16 and increased expression of Ki-67, respectively. Stratified mucin-producing intraepithelial lesion is associated with human papillomavirus, especially type 18. The weighted average risk of concurrent high-grade squamous intraepithelial lesion was 79% (range = 33%-93%), adenocarcinoma in situ 39% (2.9%-92%), adenocarcinoma 5% (1%-25%), and squamous cell carcinoma 6% (0%-11%). Patients underwent follow-up ranging from repeat Pap to radical hysterectomy, with pathology on follow-up infrequently and irregularly reported.

CONCLUSIONS

Stratified mucin-producing intraepithelial lesion is a rare lesion with a paucity of research on necessary cytology and IHC stains for diagnosis, but p16 and Ki-67 IHC stains can be performed to rule out benign lesions. The lesion is associated with high risk of concurrent high-grade squamous intraepithelial lesion, adenocarcinoma in situ, and invasive carcinoma, but studies on the risk of pursuing fertility-preserving management are needed.

Carcinomas of the Uterine Cervix: Comprehensive Review With An Update on Pathogenesis, Nomenclature of Precursor and Invasive Lesions, and Differential Diagnostic Considerations

Most cervical carcinomas and their related lesions are attributed to an infection by human papillomavirus (HPV). The infection usually starts in the basal cells at the squamocolumnar junction. It causes cell proliferation and maturation abnormalities along with nuclear abnormalities resulting in low-grade squamous intraepithelial lesions. An overwhelming majority of these lesions spontaneously disappear, and the infection is cleared. In a small subset of high-risk HPV infection cases, the lesions may persist and progress to high-grade squamous intraepithelial lesions. These are associated with the incorporation of the viral genome into the human genome. Some of the high-grade squamous intraepithelial lesions, over several years, progress to invasive carcinoma. Carcinomas of the cervix are usually squamous cell carcinomas (SCCs), but 20% to 25% of the cases may manifest as adenocarcinomas. Similar to SCC, adenocarcinomas may initially manifest as adenocarcinomas in situ and may progress to invasive carcinomas after a variable period of time. In the recently published World Health Organization classification of female genital tumors, SCCs, and adenocarcinomas of the cervix are divided into HPV-associated and HPV-independent tumors. This review draws on the latest terminology and the several morphologic subtypes recognized for each category.

Invasive Stratified Mucinous Carcinoma (iSMC) of the Cervix Often Presents With High-risk Features That Are Determinants of Poor Outcome: An International Multicenter Study

Invasive stratified mucinous carcinoma (iSMC) has been suggested to represent an aggressive subtype of endocervical adenocarcinoma. We sought to investigate the outcomes of iSMC and determine which clinical and pathologic parameters may influence the prognosis. Slides from 52 cases of iSMC were collected and classified as follows: pure iSMC (>90% of the entire tumor) and iSMC mixed with other human papillomavirus-associated adenocarcinoma components (miSMC) (>10%, but <90% of the entire tumor). Clinical and pathologic parameters were evaluated and compared with overall survival (OS) and recurrence-free survival (RFS). One third of patients with iSMC presented with lymph node metastases (LNM) and 25% developed local recurrences, whereas 4 (7.7%) developed distant recurrences. 29 cases (55.8%) were pure iSMC, whereas 23 cases (44.23%) were miSMC. OS was 74.7% in pure iSMC versus 85.2% in miSMC (P=0.287). RFS was 56.5% in pure iSMC and 72.9% in miSMC (P=0.185). At 5 years, OS in stage I was 88.9% versus stage II to IV 30% (P=0.004), whereas RFS in stage I was 73.9% versus stage II to IV 38.1% (P=0.02). OS was influenced by International Federation of Gynecology and Obstetrics (FIGO) stage (P=0.013), tumor size (P=0.02), LNM (P=0.015), and local recurrence (P=0.022), whereas RFS was influenced by FIGO stage (P=0.031), tumor size (P=0.001), local recurrence (P=0.009), LNM (P=0.008), and type of surgical treatment (P=0.044). iSMC is an aggressive cervical tumor biologically different from other human papillomavirus-associated adenocarcinomas due to the propensity for LNM, local/distant recurrence. FIGO stage, tumor size, LNM, and presence of local/pelvic recurrences are determinants of outcome in iSMCs.

Invasive Stratified Mucin-producing Carcinoma (ISMC) of the Cervix: A Study on Morphologic Diversity

Invasive stratified mucin-producing carcinoma (ISMC) is a recently described tumor with similar morphology to the stratified mucin-producing intraepithelial lesion. Stratified mucin-producing intraepithelial lesion and ISMC likely arise from human papillomavirus (HPV)-infected reserve cells in the cervical transformation zone that retain their pluripotential ability to differentiate into various architectural and cytologic patterns. This is important, as small studies have suggested that ISMC may be a morphologic pattern associated with more aggressive behavior than usual HPV-associated adenocarcinoma. We sought to study the morphologic spectrum of this entity and its associations with other, more conventional patterns of HPV-associated carcinomas. Full slide sets from 52 cases of ISMC were reviewed by an international panel of gynecologic pathologists and classified according to the new International Endocervical Criteria and Classification system. Tumors were categorized as ISMC if they demonstrated stromal invasion by solid nests of neoplastic cells with at least focal areas of mucin stratified throughout the entire thickness, as opposed to conventional tall columnar cells with luminal gland formation. Tumors comprising pure ISMC, and those mixed with other morphologic patterns, were included in the analysis. Twenty-nine pure ISMCs (56%) and 23 ISMCs mixed with other components (44%) were identified. Other components included 13 cases of usual-type adenocarcinoma, 6 adenosquamous carcinoma, 3 mucinous-type adenocarcinoma, 1 high-grade neuroendocrine carcinoma. ISMC displayed architectural diversity (insular, lumen-forming, solid, papillary, trabecular, micropapillary, single cells) and variable cytologic appearance (eosinophilic cytoplasm, cytoplasmic clearing, histiocytoid features, glassy cell-like features, signet ring-like features, bizarre nuclei, squamoid differentiation). Awareness of the spectrum of morphologies in ISMC is important for accurate and reproducible diagnosis so that future studies to determine the clinical significance of ISMC can be conducted.

The Evolving Spectrum of Precursor Lesions of Cervical Adenocarcinomas

Modern classification schemes divide cervical adenocarcinomas into human papillomavirus (HPV)-associated and HPV-independent types. The precursor lesions of the former are well known and comprise HPV-associated (usual/endocervical) adenocarcinoma in situ (AIS) and the much less common stratified mucin-producing intraepithelial lesion (SMILE). The precursor lesions of HPV-independent cervical adenocarcinomas are much less well known, although postulated precursors of gastric-type adenocarcinoma include atypical lobular endocervical glandular hyperplasia and gastric-type AIS. In this review, we cover HPV-associated and HPV-independent precursor lesions of cervical adenocarcinomas concentrating on diagnostic criteria (morphology and immunophenotype) and differential diagnosis. We propose a uniform terminology and diagnostic criteria for precursor lesions showing intestinal differentiation with goblet cells because this may be a feature of both HPV-associated and HPV-independent AIS.

Cervical adenocarcinoma: integration of HPV status, pattern of invasion, morphology and molecular markers into classification

Cervical adenocarcinoma is a heterogenous group of tumours with various aetiologies, molecular drivers, morphologies, response to treatment and prognosis. It has become evident that human papillomavirus (HPV) infection does not drive all adenocarcinomas, and appropriate classification is critical for patient management, especially in the era of the HPV vaccine and HPV-only screening. Identified as one of the most important developments in gynaecological pathology during the past 50 years, the separation of cervical adenocarcinomas into HPV-associated (HPVA) and HPV-independent has resulted in a transformation of the classification system for cervical adenocarcinomas. HPVA has been traditionally subclassified by morphology, such as usual type (UEA), mucinous and villoglandular, etc. However, it has become evident that cell type-based histomorphological classification is not clinically meaningful, and the newly proposed International Endocervical Adenocarcinoma Criteria and Classification (IECC) is a necessary and relevant break from this prior system. Non-HPV-associated adenocarcinomas can be divided by their distinct morphology and molecular genomics with very different responses to standard therapies and potential for future targeted therapies. These include gastric-type, clear-cell, mesonephric and endometrioid adenocarcinomas. So-called 'serous' carcinomas of the cervix probably represent morphological variants of UEA or drop metastases from uterine or adnexal serous carcinomas, and the existence of true cervical serous carcinomas is in question. This review will discuss the advances since WHO 2014, and how HPV status, pattern of invasion as described by Silva and colleagues, histological features and molecular markers can be used to refine diagnosis and prognostication for patients with cervical adenocarcinoma.

Conjunctival 'mucoepidermoid carcinoma' revisited: a revision of terminology, based on morphologic, immunohistochemical and molecular findings of 14 cases, and the 2018 WHO Classification of Tumours of the Eye

In 2018, the consensus meeting for the WHO Classification of Tumours of the Eye decided that conjunctival mucoepidermoid carcinoma should be reclassified as adenosquamous carcinoma, as this represented a better morphological fit. To examine the applicability of this terminology, we studied the clinical, histopathological, immunohistochemical and molecular pathology of 14 cases that were originally diagnosed as conjunctival mucoepidermoid carcinoma. There were 7 (50%) females and 7 (50%) males. The median age was 64 years. The left eye was affected in 8 and the right eye in 6 patients. In-situ carcinoma was present in 11/14 (79%) cases and comprised in-situ squamous cell carcinoma (SCC) and conjunctival intraepithelial neoplasia with mucinous differentiation (CIN-Muc). Invasive carcinoma was present in 11/14 (79%) cases. Group 1 (1/11 cases, 9%) comprised invasive SCC only. Group 2 (6/11 cases, 55%) comprised SCC with mucinous differentiation, manifesting as scattered intracellular mucin, occasionally together with intercellular mucin, with no evidence of true glandular differentiation. Group 3 (3/11 cases. 27%) comprised true adenosquamous carcinoma. Group 4 (1/11 cases, 9%) comprised pure adenocarcinoma. Thirteen of 14 cases (93%) underwent FISH for MAML2 translocation and none were rearranged. Two cases harboured high-risk HPV (type 16 and 18). The combined findings confirm that all lesions in our study were not mucoepidermoid carcinoma, but represented predominantly SCC with mucinous differentiation and adenosquamous carcinoma. We, therefore, recommend future revision of the WHO classification to include SCC with mucinous differentiation alongside adenosquamous carcinoma.

Moving forward-the 2019 ASCCP Risk-Based Management Consensus Guidelines for Abnormal Cervical Cancer Screening Tests and Cancer Precursors and beyond: implications and suggestions for laboratories

The 2019 ASCCP Risk Based Management Consensus Guidelines for prevention of cervical cancer promote clinical management recommendations aligned with our increased understanding of HPV biology and cervical carcinogenesis. They employ HPV-based testing as the basis for risk estimation, allow for personalized risk-based management by incorporating knowledge of current results with prior results, and streamline incorporation of new test methods as they are validated. They continue to support the principles of "equal management for equal risk" and "balancing harms and benefits" adopted in the 2012 version of the guidelines. These updated guidelines will be able to adjust for decreasing CIN3+ risks as more patients who received HPV vaccination reach screening age. Pathology organizations were closely involved in the development of these guidelines. Herein the pathologists who served as representatives to the 2019 ASCCP guidelines steering committee and workgroups, summarize the changes that are relevant to laboratories, pathologists, and cytotechnologists. Prior relevant screening and reporting recommendations that have not been widely and/or inconsistently adopted by laboratories are also discussed and considerations for modification of laboratory practices offered.

Is hysterectomy necessary for the treatment of preinvasive stratified mucin producing intraepithelial lesions of the cervix?

OBJECTIVES

Stratified mucin producing intraepithelial lesion (SMILE) is an uncommon premalignant cervical intraepithelial lesion, characterized by histopathologic features resembling those observed in high grade squamous intraepithelial lesions and adenocarcinoma in situ of the cervix. Its hybrid morphology poses a pathologic challenge with no specific management guidelines. The goal of this study was to review the natural history of SMILE and treatment based outcomes.

METHODS

A retrospective pathology review of all cases of cervical intraepithelial lesions, with confirmation of all SMILE lesions, at one institution between 2007 and 2019, was performed. Clinical and pathologic characteristics, management options, and patient outcomes were reviewed and analyzed. Inclusion criteria included all patients diagnosed initially with SMILE on biopsy, excisional procedure, or simple hysterectomy. Patients diagnosed with SMILE had to fulfill the following pathologic features: stratified columnar epithelium with nuclear atypia and mucin production throughout the epithelial thickness with increased mitotic activity, and/or apoptotic bodies. Pathologic slides were re-evaluated by a pathologist to confirm the diagnosis and review margin status.

RESULTS

24 patients with SMILE were identified. Mean age at diagnosis was 36.2 years (range 25-53) with 67% (16/24) diagnosed before the age of 40. The majority (54%, 13/24) were nulliparous and 63% (15/24) had a past history of abnormal Pap smears. 92% (22/24) of patients were positive for high risk human papillomavirus, with 13% (n=3) presenting with a normal Pap smear. Diagnosis was made primarily on colposcopy (n=16), cold knife cone/loop electrosurgical excision procedure (n=7), or hysterectomy (n=1). Most patients (71%, 17/24) had a co-existing precancerous lesion at the time of diagnosis and the most common was high grade squamous intraepithelial lesion (53%). Five invasive lesions were also identified at the time of diagnosis of SMILE (2 adenocarcinoma, 3 adenosquamous), 1 of which underwent chemoradiation. Among all patients, 25% (6/24) underwent hysterectomy (4 simple, 2 radical), while 63% (17/24) of patients underwent a fertility sparing excisional procedure; 4% (1/24) were incidentally diagnosed on hysterectomy. 18 patients had negative margins and 2 patients had positive margins. Over a median follow-up of 29 months (range 3-105), all of the fertility sparing patients with negative margins had no recurrence. Among the two patients with positive margins, one had no recurrence on repeat excision and the other underwent repeat excision with persistent SMILE identified, subsequent negative margin, and no recurrence since.

DISCUSSION

Our data showed that most patients with SMILE were young, positive for high risk human papillomavirus, nulliparous, and presented with coexisting lesions. Excisional procedures with negative margins may be sufficient fertility sparing treatment in patients with preinvasive SMILE with a low risk of recurrence. There should be consideration of hysterectomy at the completion of childbearing.

Clinical Outcomes of HPV-associated and Unassociated Endocervical Adenocarcinomas Categorized by the International Endocervical Adenocarcinoma Criteria and Classification (IECC)

The International Endocervical Adenocarcinoma Criteria and Classification (IECC) categorizes endocervical adenocarcinomas (ECAs) on the basis of morphologic features linked to etiology (ie, human papilloma virus [HPV] infection), resulting in separation of ECAs into HPV-associated (HPVA) and unassociated or non-HPVA (NHPVA) types. NHPVAs are reported to be large and present at high stage in older individuals. Our aim was to examine the clinical outcomes in these tumor types. Full slide sets of 205 ECAs were collected from 7 institutions worldwide and classified on the basis of IECC criteria and the presence or absence of HPV. Clinical and morphologic parameters were correlated with follow-up data. Statistical analysis of overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS) were conducted using the Kaplan-Meier survival analysis and compared using the log-rank test for univariate analysis. Multivariate survival analysis was conducted, and the survival endpoints considered were OS, DFS, and PFS. Statistically significant survival differences (OS, DFS, and PFS) were found when comparing the following categories: HPVA>NHPVA (ie, survival was superior in the setting of HPVAs), including patients treated with surgery followed by adjuvant therapy; usual-type HPVA>mucinous HPVA; FIGO grade 3 HPVA>NHPVA; HPVA>NHPVA, both with lymphovascular invasion; and HPVA>NHPVA in patients with pelvic recurrences. Although there were trends favoring HPVA outcomes over those of NHPVA, these differences were not statistically significant in the following categories: mucinous HPVA versus NHPVA; HPVA versus NHPVA, both with lymph node metastases at presentation; and HPVA versus NHPVA in patients with distant metastasis. Survival for both HPVA and NHPVA was similar when surgery without adjuvant therapy was used. FIGO grading did not have prognostic significance in HPVAs. Multivariable analysis of HPVAs indicated nearly significant statistical associations between stage and both OS and DFS (P=0.07 and 0.06, respectively), and between Silva invasion pattern and OS (P=0.09). Multivariate analysis of NHPVAs indicated a statistically significant association between OS and age (P=0.03), stage (P=0.02) and tumor size (P=0.002), and between DFS and stage (P=0.004) and tumor size (P=0.004). Multivariate analysis of HPVAs and NHPVAs together revealed nearly significant associations between OS and HPV status and stage (both [P=0.06]). For DFS, stage was a significant variable (P=0.04), whereas HPV status and tumor size were nearly significant (P=0.06 and 0.07, respectively). Clinical outcome studies support the idea that the IECC classification not only separates ECAs on the basis of HPV status (usually assessed on H&E slides), but also has important clinical relevance.

Human Papilloma Virus-Associated Squamous Neoplasia of the Lower Anogenital Tract

HPV-associated squamous neoplasias of the lower anogenital tract are biologically and morphologically equivalent; a unified, two-tiered nomenclature system is recommended to reflect this. Low-grade squamous intraepithelial lesion represents the morphologic manifestation of transient HPV infection with high rate of regression. High-grade squamous intraepithelial lesion (HSIL) represents the morphologic manifestation of persistent high-risk HPV infection and viral integration with a significant rate of progression to invasive carcinoma. Despite these shared attributes, SILs encounter unique diagnostic challenges by anatomic site. This article discusses the LAST project recommendations, challenges associated with their application, and site specific diagnostic challenges in their relevant clinical context.

[The 2019 FIGO classification for cervical carcinoma-what's new?]

Numerous therapeutic and prognostic studies of cervical carcinoma have necessitated a revision of the FIGO classification.For microinvasive carcinomas, the horizontal dimension is no longer considered and diagnosis and staging will solely be made by the depth of cervical stromal invasion. Lymphovascular invasion beyond the deepest point of stromal infiltration by tumor cells does not alter the stage.There will be a new subclassification of macroinvasive carcinoma confined to the uterine cervix, which will be made by largest tumor extension as follows: FIGO IB1/T1b1 - invasive carcinoma >0.5 cm depth of stromal invasion and ≤2 cm in largest dimension, FIGO IBII/T1b2: - invasive carcinoma >2 cm and ≤4 cm, FIGO IBII/T1b3 - invasive carcinoma >4 cm. Pelvic as well as para-aortic lymph nodes will be defined as regional nodes. Pelvic lymph node metastases only will be categorised as FIGO IIIC1/pN1a and para-aortic lymph node involvement with or without concomitant pelvic involvement will be FIGO IIIC2/pN1b. Uterine corpus as well as adnexal involvement are not relevant for staging purpose.

Invasive stratified mucin-producing carcinoma (i-SMILE) of the uterine cervix: report of a case series and review of the literature indicating poor prognostic subtype of cervical adenocarcinoma

PURPOSE

Invasive stratified mucin-producing carcinoma (i-SMILE) represents a recently recognized subtype of cervical adenocarcinoma (AC) developing in a background of a stratified mucin-producing intraepithelial lesion (SMILE). Clinical and prognostic data on i-SMILE are limited.

METHODS

We report a series of five cases with histopathological, immunohistochemical (p16) and PCR analyses. The cases as well as the patients previously published in the literature were reviewed for follow-up information.

RESULTS

Thirteen cases were identified. The mean age of 47.1 years (range 34-66) was not different from the usual type of cervical AC. 10/13 cases presented with tumors > 2 cm and a polypoid-exophytic appearance. Regardless of tumor size and stage of the disease, 7 out of 11 patients developed recurrent disease after a mean of 7.8 months (range 6 weeks-36 months). Five patients developed distant metastases (three of them in the lungs). Five out of the 11 informative cases died of the disease. All reported cases were positive for high-risk HPV (mainly HPV type 18) and associated with p16-overexpression.

CONCLUSION

i-SMILE represent a distinct subtype of invasive endocervical AC, associated high-risk HPV infection and strong p16-overexpression. Clinically, i-SMILE may represent an aggressive tumor with early recurrent disease and substantial risk of distant metastatic disease, especially to the lungs.

Invasive stratified mucin-producing carcinoma: a clinicopathological analysis of three cases

Objective: To investigate the clinicopathologic features and immunophenotype of invasive-stratified mucin-producing carcinoma (ISMC). Methods: We retrospectively analyzed three patients who underwent surgery for pathologically confirmed ISMC from January 2017 to December 2017 in Anyang Tumor Hospital. The pathological features, immunophenotype, and prognosis were discussed. Results: Clinical symptoms and imaging were atypical. Microscopically, the arrangement of tumor cells is close to that of squamous cell carcinoma, showing flake or nested growth. Morphologically, tumor cells were reminiscent of adenocarcinoma. The tumor cells showed abundant intracytoplasmic mucus which routinely created spacing between adjacent nuclei. The nuclei was round or oval with irregular karyotypes, thick nuclear membrane, staining empty light, rough chromatin, visible small nucleoli. Mucous vacuoles or pink-stained foam were visible in the cytoplasm. Mitotic features and apoptotic bodies were seen in the invasive component of all three cases, whereas all but one of these showed a neutrophil-dominant inflammatory cells infiltration. A large number of histocytes were found in the stroma of two cases. Special staining of mucus confirmed the presence of mucus in cytoplasm. Immunohistochemical results showed that tumor cells were strongly and diffusely positive for p16 and CK7 and had high Ki-67 expression. Conclusions: ISMC is a rare tumor in female genital tract and is often misdiagnosed as squamous cell carcinoma and other cervical cancers. The diagnosis mainly depends on the unique clinicopathologic features together with the immunophenotype. Treatment and prognosis, like other cervical cancer, are mainly based on clinical stages.

Detection of HPV RNA molecules in stratified mucin-producing intraepithelial lesion (SMILE) with concurrent cervical intraepithelial lesion: a case report

Background

Stratified mucin-producing intraepithelial lesion (SMILE) is a rare precursor lesion in the uterine cervix that is considered a variant of adenocarcinoma in situ (AIS). Although human papillomavirus (HPV) is thought to be related to the development of SMILE, there is little information available on the detection of HPV integrated into the lesion.

Case presentation

A 30-year-old female underwent a routine uterine cervical cancer screening, and her Pap smear indicated the possible existence of atypical glandular cells. A cervical biopsy with endocervical curettage was performed. The histopathological analysis showed that she had SMILE and high-grade squamous intraepithelial lesion (HSIL) on her cervix. The lesion was found to be positive for HPV genotypes 52 and 68 by multiplex PCR. In situ hybridization with HPV RNA probes revealed that these HPV types were involved in the onset of HSIL and SMILE, respectively.

Conclusions

Rare, high-risk HPV genotypes may contribute to the development of SMILE, and their detection can be useful for preventing the progression to carcinoma and ensuring adequate patient management.

Cervical Glandular Neoplasia: Classification and Staging

Endocervical adenocarcinomas (EAs) account for 25% of all primary cervical carcinomas. Approximately 85% of EAs are driven by high-risk human papillomavirus (HPV) infection, the most common of which is the so-called usual type endocervical adenocarcinomas. Non-HPV-driven subtypes harbor distinct clinicopathologic features and prognosis and have been increasingly recognized in recent years, which has led to efforts to improve classification of EA based on clinically relevant and reproducible criteria. This review discusses a recently proposed classification system, the International Endocervical Adenocarcinoma Criteria and Classification, which uniquely integrates morphology, cause/pathogenesis, and biological behavior of HPV and non-HPV-driven subtypes of EA.

RETRACTED ARTICLE: Cervical adenosquamous carcinoma: detailed analysis of morphology, immunohistochemical profile, and clinical outcomes in 59 cases

Although 2014 World Health Organization criteria require unequivocal glandular and squamous differentiation for a diagnosis of cervical adenosquamous carcinoma, in practice, adenosquamous carcinoma diagnoses are often made in tumors that lack unequivocal squamous and/or glandular differentiation. Considering the ambiguous etiologic, morphological, and clinical features and outcomes associated with adenosquamous carcinomas, we sought to redefine these tumors. We reviewed slides from 59 initially diagnosed adenosquamous carcinomas (including glassy cell carcinoma and related lesions) to confirm an adenosquamous carcinoma diagnosis only in the presence of unequivocal malignant glandular and squamous differentiation. Select cases underwent immunohistochemical profiling as well as human papillomavirus (HPV) testing by in situ hybridization. Of the 59 cases originally classified as adenosquamous carcinomas, 34 retained their adenosquamous carcinoma diagnosis, 9 were reclassified as pure invasive stratified mucin-producing carcinomas, 10 as invasive stratified mucin-producing carcinomas with other components (such as HPV-associated mucinous, usual-type, or adenosquamous carcinomas), and 4 as HPV-associated usual or mucinous adenocarcinomas with benign-appearing squamous metaplasia. Two glassy cell carcinomas were reclassified as poorly differentiated usual-type carcinomas based on morphology and immunophenotype. There were significant immunophenotypic differences between adenosquamous carcinomas and pure invasive stratified mucin-producing carcinomas with regard to HPV (p < 0.0001), PAX8 (p = 0.038; more in adenosquamous carcinoma), p40 (p < 0.0001; more in adenosquamous carcinoma), p63 (p = 0.0018; more in adenosquamous carcinoma) and MUC6 (p  < 0.0001; less in adenosquamous carcinoma), HNF-1beta (p = 0.0023), vimentin (p = 0.0003), p53 (p = 0.0004), and CK7 (p = 0.0002) expression. Survival outcomes were similar between all groups. Adenosquamous carcinomas should be diagnosed only in the presence of unequivocal malignant glandular and squamous differentiation. The two putative glassy cell carcinomas studied did not meet our criteria for adenosquamous carcinoma, and categorizing them as such should be reconsidered.

Cervical Adenocarcinomas: A Heterogeneous Group of Tumors With Variable Etiologies and Clinical Outcomes

Context.—

Cervical adenocarcinomas are a heterogeneous group of tumors with varying morphologies, etiologies, molecular drivers, and prognoses, comprising approximately 25% of all cervical cancers. Unlike cervical squamous cell carcinoma, adenocarcinomas are not uniformly caused by high-risk human papillomavirus (HPV) infection and, therefore, would not necessarily be prevented by the HPV vaccine.

Objective.—

To provide a review of endocervical adenocarcinoma subtypes and, when appropriate, discuss precursor lesions, etiologies, molecular genetics, and ancillary studies within the context of clinical care. Some historical perspectives will also be provided.

Data Sources.—

Data sources included published peer-reviewed literature and personal experiences of the senior author.

Conclusions.—

Endocervical adenocarcinomas are a histologically diverse group of tumors with various causes and molecular drivers, not all related to HPV infection. Distinguishing them has important implications for treatment and prognosis as well as strategies for prevention.

International Endocervical Adenocarcinoma Criteria and Classification: Validation and Interobserver Reproducibility

The current World Health Organization (WHO) classification for endocervical adenocarcinoma (EA) is based on descriptive morphologic characteristics; however, it does not fully reflect our current knowledge of the diverse pathogenesis of cervical glandular neoplasia. A novel classification system, the International Endocervical Adenocarcinoma Criteria and Classification (IECC), which incorporates etiology and biological behavior into the morphologic scheme, has been recently proposed. We aimed to validate the IECC by assessing its interobserver reproducibility in comparison to the WHO system. A cohort of 75 EAs was reviewed independently by 7 gynecologic pathologists and categorized following IECC and WHO criteria based on hematoxylin and eosin material alone and after immunohistochemistry results for p16, PR, p53, Napsin-A, vimentin, CDX2, and GATA3 were provided. Human papillomavirus (HPV) in situ hybridization and polymerase chain reaction results were compared with consensus diagnoses. IECC was superior to WHO in terms of interobserver agreement with κ=0.46 versus 0.3, respectively, on hematoxylin and eosin review and κ=0.51 versus 0.33, respectively, with immunohistochemistry. Under the IECC, 73 (97%) of EAs had majority agreement (≥4 reviewers in agreement) whereas 42 (56%) had perfect agreement (7/7 reviewers in agreement). Conversely, WHO showed majority agreement in 56 (75%) and perfect agreement in only 7 (10%) EAs. Reproducibility was poor in HPV-related WHO types (usual κ=0.36, mucinous not otherwise specified κ=0.13, intestinal κ=0.31, villoglandular κ=0.21) and good in major HPV-unrelated categories (gastric type κ=0.63, clear cell κ=0.81, mesonephric κ=0.5). Classification as per the IECC had excellent correlation with HPV status (by RNA in situ hybridization or polymerase chain reaction). We have shown that the IECC has superior interobserver agreement compared with the WHO classification system, and that distinction between HPV-related and HPV-unrelated EA can be made with good reproducibility and excellent prediction of HPV status. WHO morphologic variants of HPV-related EA are poorly reproducible. Conversely, agreement is high among important high-risk HPV-unrelated subtypes. Thus, our results further support replacing the current WHO classification with the IECC.

International Endocervical Adenocarcinoma Criteria and Classification (IECC): A New Pathogenetic Classification for Invasive Adenocarcinomas of the Endocervix

We sought to classify endocervical adenocarcinomas (ECAs) based on morphologic features linked to etiology (ie, human papillomavirus [HPV] infection), unlike the World Health Organization 2014 classification. The International Endocervical Adenocarcinoma Criteria and Classification (IECC criteria), described herein, distinguishes between human papillomavirus-associated adenocarcinoma (HPVA), recognized by the presence of luminal mitoses and apoptosis seen at scanning magnification, and no or limited HPVA features (nonhuman papillomavirus-associated adenocarcinoma [NHPVA]). HPVAs were then subcategorized based on cytoplasmic features (mostly to provide continuity with preexisting classification schemes), whereas NHPVAs were subclassified based on established criteria (ie, gastric-type, clear cell, etc.). Complete slide sets from 409 cases were collected from 7 institutions worldwide. Tissue microarrays representing 297 cases were constructed; immunohistochemistry (p16, p53, vimentin, progesterone receptor) and chromogenic in situ hybridization using an RNA-based probe set that recognizes 18 varieties of high-risk HPV were performed to validate IECC diagnoses. The 5 most common IECC diagnoses were usual-type (HPVA) (73% of cohort), gastric-type (NHPVA) (10%), mucinous adenocarcinoma of HPVA type, including intestinal, mucinous not otherwise specified, signet-ring, and invasive stratified mucin-producing carcinoma categories (9%), clear cell carcinoma (NHPVA) (3%) and adenocarcinoma, not otherwise specified (2%). Only 3 endometrioid carcinomas were recognized and all were NHPVA. When excluding cases thought to have suboptimal tissue processing, 90% and 95% of usual-type IECC cases overexpressed p16 and were HPV, whereas 37% and 3% of NHPVAs were p16 and HPV, respectively. The 1 HPV gastric-type carcinoma was found to have hybrid HPVA/NHPVA features on secondary review. NHPVA tumors were larger and occurred in significantly older patients, compared with HPVA tumors (P<0.001). The high-risk HPV chromogenic in situ hybridization probe set had superior sensitivity, specificity, and positive and negative predictive values (0.955, 0.968, 0.992, 0.833, respectively) compared with p16 immunohistochemistry (0.872, 0.632, 0.907, 0.545, respectively) to identify HPV-related usual carcinoma and mucinous carcinoma. IECC reliably segregates ECAs into HPVA and NHPVA types using morphology alone. This study confirms that usual-type ECAs are the most common type worldwide and that mucinous carcinomas comprise a mixture of HPVA and NHPVA, with gastric-type carcinoma being the major NHPVA type. Endometrioid and serous carcinomas of the endocervix are extraordinarily rare. Should clinical outcomes and genomic studies continue to support these findings, we recommend replacement of the World Health Organization 2014 criteria with the IECC 2017.

[The morphological and immunohistochemical characteristics of stratified mucin-producing intraepithelial lesion]

Stratified mucin-producing intraepithelial lesion (SMILE) is a rare premalignant cervical lesion that combines the structural features of cervical intraepithelial neoplasia (CIN) and endocervical adenocarcinoma in situ (AIS).

AIM

to analyze archival materials for the detection of SMILE and its subsequent morphological and immunohistochemical characterization.

MATERIAL AND METHODS

Cervical cone specimens from 53 women with histologically verified CIN3 were examined. The diagnosis of SMILE was based on the positive mucicarmine staining and weak focal expression of p63. The samples containing SMILE were further immunohistochemically examined using the biomarkers P16, Ki-67, Oct4, CD117, CD34, p53, EMA, and CK15. SMILE was detected in 2 of the 53 patients and concurrent with CIN3 in both cases. SMILE was characterized by the stratified arrangement of atypical cells containing mucin, the positive mucicarmine staining of the entire layer of the atypical epithelium, weak focal p63 expression, high Ki-67 expression, and diffuse р16Іnk4а staining. Both SMILE samples showed weak diffuse p53 expression in the presence of single cells with the pronounced nuclear staining pattern for p53 in one female patient. Weak focal CK15 expression was visualized in SMILE. The expression of the stem cell markers Oct4 and CD117 and the angiogenic marker CD34 was absent in the examined cervical epithelial preparations. The diffuse and intense expression of the marker EMA, which was not different from that in the endocervical and stratified squamous epithelium, and CIN3 was established in SMILE.

RESULTS

The findings suggest that SMILE is morphologically and immunohistochemically similar to CIN3. In this investigation, these abnormalities differed only in the mucicarmine staining and expression of p63. This may be indicative of the underdiagnosis of SMILE, attendant СIN3 in the routine practice of a clinical pathologist, as the diagnosis of CIN3 is primarily based on the results of assessment of only the preparations stained with hematoxylin and eosin; the expression of p16 and Ki-67 is evaluated in some cases, which fails to differentiate SMILE and CIN3 in a number of preparations.

CONCLUSION

The diagnosis of SMILE can be made only by immunohistochemical examination.

[Categorization of uterine cervix tumors : What's new in the 2014 WHO classification]

In the 2014 WHO classification, squamous cell precursor lesions are classified as low-grade and high-grade intraepithelial lesions. LSIL corresponds to CIN1, HSIL includes CIN2 and CIN3. Only adenocarcinoma in situ (AIS) is accepted as precursor of adenocarcinoma and includes the stratified mucin-producing intraepithelial lesion (SMILE). Although relatively rare, adenocarcinoma and squamous cell carcinoma can be mixed with a poorly differentiated neuroendocrine carcinoma. Most cervical adenocarcinomas are low grade and of endocervical type. Mucinous carcinomas show marked intra- and extracellular mucin production. Almost all squamous cell carcinomas, the vast majority of adenocarcinomas, and many rare carcinoma types are HPV related. For low grade endocervical adenocarcinomas, the pattern-based classification according to Silva should be reported. Neuroendocrine tumors are rare and are classified into low-grade and high-grade, whereby the term carcinoid is still used.

Deciphering the Multifactorial Susceptibility of Mucosal Junction Cells to HPV Infection and Related Carcinogenesis

Human papillomavirus (HPV)-induced neoplasms have long been considered to originate from viral infection of the basal cell layer of the squamous mucosa. However, this paradigm has been recently undermined by accumulating data supporting the critical role of a discrete population of squamo-columnar (SC) junction cells in the pathogenesis of cervical (pre)cancers. The present review summarizes the current knowledge on junctional cells, discusses their high vulnerability to HPV infection, and stresses the potential clinical/translational value of the novel dualistic model of HPV-related carcinogenesis.

Penile Analogue of Stratified Mucin-Producing Intraepithelial Lesion of the Cervix: The First Described Case. A Diagnostic Pitfall

The authors report a case where undifferentiated (classic) penile intraepithelial neoplasia was associated with the presence of goblet cells throughout the full epithelial thickness and which later progressed into an invasive carcinoma. The lesion evolved in three consecutive biopsies from only surface epithelium occupying numerous goblet cells in the first to variably sized solid nodules in the dermis composed of atypical squamous and/or basaloid cells intermixed with numerous goblet cells in the third biopsy. Both cellular components expressed CK7 and p16 protein. Human Papillomavirus (HPV) genotyping revealed high risk HPV type 16. To the best of our knowledge, this is the first description of such a lesion occurring on the penis, which can be considered the penile analogue of cervical stratified mucin-producing intraepithelial lesion (SMILE). The correct diagnosis was rendered retrospectively, after recognition of the existence of a vulvar lesion resembling cervical SMILE. The initial biopsy was misinterpreted as extramammary Paget disease, which also constitutes the main pitfall in the differential diagnosis. Another important differential diagnosis is penile/vulvar mucinous metaplasia. The finding of atypical squamous epithelial cells positive for p16 associated with mucinous cells present throughout the full epithelial thickness is a clue to the diagnosis of penile SMILE.

Stratified Mucin-Producing Intraepithelial Lesion of the Cervix: Subtle Features Not to Be Missed

OBJECTIVES

Stratified mucin-producing intraepithelial lesion (SMILE) is an uncommon premalignant lesion of the uterine cervix. A detailed examination of preinvasive SMILE cases including a comparison of the cytologic features with usual-type adenocarcinoma in situ (AIS) and human papillomavirus (HPV) genotyping was performed.

STUDY DESIGN

Excisions and preceding Papanicolaou (Pap) tests were retrieved from the files of 2 tertiary care centers. Histologic review estimated the lesional SMILE proportion. Pap tests were reviewed and assessed for architectural, cellular and background features. Cobas® HPV test was performed.

RESULTS

13 cases were identified. Mean/median patient age was 35/33 years (range 23-51 years). Concurrent high-grade squamous intraepithelial lesion was found in 10/13 (77%) and AIS in 8/13 (62%) cases. In 6 cases, SMILE was dominant (≥50%) and represented in 5/6 corresponding Pap tests. Cytology interpretations differed more often in the SMILE-dominant group (p < 0.05). SMILE and AIS had overlapping features. Feathering and prominent nucleoli were absent in SMILE. HPV DNA was detected in all 12 cases tested. HPV 18 was most common (7/12). Excisions with positive/suspicious margins were reported in 5/6 SMILE-dominant versus 3/7 nondominant cases.

CONCLUSION

SMILE is best considered as an AIS variant for cytologic, etiologic and management purposes. Cytologic features overlap with AIS, but are more subtle and easily missed. HPV testing may play a role in facilitating SMILE detection.