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

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.

Stratified mucin-producing intraepithelial lesion with invasive carcinoma: 12 cases with immunohistochemical and ultrastructural findings

Stratified mucin-producing intraepithelial lesion (SMILE) is considered to be a variant of adenocarcinoma in situ (defined as intraepithelial malignant glandular epithelium without invasion) or adenosquamous carcinoma in situ of the uterine cervix. However, recent study suggested that SMILE is more similar to high-grade squamous epithelial lesion by their immunohistochemical findings. An invasive form of SMILE "invasive stratified mucin-producing carcinoma (ISMC)" has been also proposed, but immunohistochemical features are not well documented. Therefore, this study aimed to clarify the immunohistochemical characteristics of SMILE and ISMC. Twelve cases of SMILE were found among 445 patients (2.7%) with high-grade intraepithelial lesions or invasive carcinomas, 3 of whom had solely intraepithelial disease with SMILE component (mean age, 37 years; range, 30-48 years) and 9 with invasive carcinomas (mean age, 47 years; range, 37-66 years; including ISMC). Immunohistochemically, SMILE and ISMC were diffusely positive for p16 and CAM5.2, focally for IMP3, and almost negative or only focally positive for p63. Nuclear signals in SMILE and invasive carcinomas were detected by human papillomavirus (HPV) in situ hybridization; 5 cases showed HPV16 and/or HPV18 polymerase chain reaction products. The ultrastructural study of 1 case showed surface microvilli and small vacuolar structure in SMILE; ISMC had mucous-like vacuoles, many mitochondria and intracytoplasmic lumen but lacked tonofilament. These findings were more similar to adenocarcinoma in situ or adenocarcinoma than squamous intraepithelial lesion or squamous cell carcinoma. We suggest that SMILE is an intraepithelial neoplasm and ISMC is an invasive form of SMILE.

Human papillomavirus prevalence and type-distribution in cervical glandular neoplasias: Results from a European multinational epidemiological study

Cervical glandular neoplasias (CGN) present a challenge for cervical cancer prevention due to their complex histopathology and difficulties in detecting preinvasive stages with current screening practices. Reports of human papillomavirus (HPV) prevalence and type-distribution in CGN vary, providing uncertain evidence to support prophylactic vaccination and HPV screening. This study [108288/108290] assessed HPV prevalence and type-distribution in women diagnosed with cervical adenocarcinoma in situ (AIS, N = 49), adenosquamous carcinoma (ASC, N = 104), and various adenocarcinoma subtypes (ADC, N = 461) from 17 European countries, using centralised pathology review and sensitive HPV testing. The highest HPV-positivity rates were observed in AIS (93.9%), ASC (85.6%), and usual-type ADC (90.4%), with much lower rates in rarer ADC subtypes (clear-cell: 27.6%; serous: 30.4%; endometrioid: 12.9%; gastric-type: 0%). The most common HPV types were restricted to HPV16/18/45, accounting for 98.3% of all HPV-positive ADC. There were variations in HPV prevalence and ADC type-distribution by country. Age at diagnosis differed by ADC subtype, with usual-type diagnosed in younger women (median: 43 years) compared to rarer subtypes (medians between 57 and 66 years). Moreover, HPV-positive ADC cases were younger than HPV-negative ADC. The six years difference in median age for women with AIS compared to those with usual-type ADC suggests that cytological screening for AIS may be suboptimal. Since the great majority of CGN are HPV16/18/45-positive, the incorporation of prophylactic vaccination and HPV testing in cervical cancer screening are important prevention strategies. Our results suggest that special attention should be given to certain rarer ADC subtypes as most appear to be unrelated to HPV.

Stratified mucin-producing intraepithelial lesion (SMILE): report of a case series with associated pathological findings

AIMS

Stratified mucin-producing intraepithelial lesion (SMILE) is an uncommon premalignant cervical lesion showing morphological overlap with cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ (AIS)/cervical glandular intraepithelial neoplasia. Given the limited literature on SMILE, we aimed to document its frequency and assess the associated pathology in a large series of cases.

METHODS AND RESULTS

Over a 6-year period, we documented all cases of SMILE and the associated findings. SMILE was diagnosed in 69 specimens from 60 patients (50 loop excisions and 19 punch biopsy specimens), constituting 0.6% of cervical specimens. Overall, SMILE coexisted with high-grade CIN in 93% of cases, AIS in 42%, and a carcinoma in 10%. When SMILE was diagnosed on a cervical punch biopsy, there was high-grade CIN in the follow-up loop in most cases. SMILE was consistently diffusely p16-positive and IMP3-negative.

CONCLUSIONS

Given the morphological overlap and significant association with high-grade CIN and AIS, we believe that SMILE is best regarded as a form of high-grade reserve cell dysplasia, probably arising from reserve or stem cells with the capacity for multidirectional differentiation. We recommend that management of SMILE should be as for AIS.

Squamous/epidermoid differentiation in normal breast and salivary gland tissues and their corresponding tumors originate from p63/K5/14-positive progenitor cells

A small group of tumors of breast and salivary glands contains squamous/epidermoid elements as a constitutive feature (e.g., squamous carcinoma, syringomatous tumors, and mucoepidermoid carcinoma). Other tumors (e.g., pleomorphic adenoma, adenomyoepithelial tumors, and adenoid cystic carcinoma) may show occasionally squamous differentiation. Furthermore, squamous metaplasia may be observed in non-neoplastic breast and salivary tissues. However, the histogenesis of these squamous differentiations is far from being understood. Based on our earlier in situ triple immunofluorescence and quantitative reverse transcription (RT)-PCR experiments for basal keratins K5/14 and p63 as well as for glandular keratins (K7/K8/18), squamous keratins (K10 and K13), and myoepithelial lineage markers (smooth muscle actin, SMA), we here traced the squamous/epidermoid differentiation lineage of 60 tumors of the breast and/or salivary glands, cultured tumor cells of 2 tumors, and of 7 squamous metaplasias of non-neoplastic breast and salivary tissues. Our results indicate that both the neoplastic lesions as well as the non-neoplastic squamous metaplasia contain p63/K5/14+ cells that differentiate toward K10/13+ squamous cells. Thus, cells with squamous/epidermoid differentiation undergo a transition from its original p63/K5/14+ precursor state to K10/13+ squamous lineage state, which can be pictured by triple-immunofluorescence experiments. Given the immunophenotypic similarity of p63/K5/14+ tumor cells to their physiological p63/K5/14+ counterparts in normal breast and salivary duct epithelium, we suggest that these cells provide an important histogenetic key to understanding the pathogenesis of squamous differentiation both in normal breast/salivary gland tissues and their corresponding tumors.

The spectrum of cervical glandular neoplasia and issues in differential diagnosis

CONTEXT

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

OBJECTIVE

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

CONCLUSIONS

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

The utility of p63, p40, and GATA-binding protein 3 immunohistochemistry in diagnosing micropapillary urothelial carcinoma

Micropapillary urothelial carcinoma (MPUC) is an uncommon variant of urothelial carcinoma (UC) with an aggressive clinical course. There have been limited studies on the UC markers GATA-binding protein 3 (GATA3), p63, and p40 in MPUC. Our study investigated the immunoreactivity of these 3 markers in MPUC compared with conventional UC of different grades and stages. Immunohistochemistry was performed on 62 cases of high-grade urothelial carcinoma (HGUC), 16 low-grade urothelial carcinoma (LGUC), and 20 MPUC. p63 expression was strong and diffuse in all LGUC, significantly decreased in high stage and HGUC, and virtually absent in MPUC. p40 expression was decreased in HGUC and markedly decreased in MPUC relative to LGUC. These results suggest that loss of p63 expression in a UC appears to be associated with adverse features--including cases with micropapillary differentiation. Decreased GATA3 expression was seen frequently in high-grade and high-pathologic stage (≥pT2) tumors but was retained in MPUC cases. The findings of retained GATA3 expression in MPUC, which often shows a loss of expression of other urothelial markers such as p63, may be helpful for determining the origin of micropapillary carcinoma of unknown primary. Compared with the traditional markers p63 and p40, GATA3 is the most sensitive marker of conventional UC and MPUC.

deltaNp63 has a role in maintaining epithelial integrity in airway epithelium

The upper airways are lined with a pseudostratified bronchial epithelium that forms a barrier against unwanted substances in breathing air. The transcription factor p63, which is important for stratification of skin epithelium, has been shown to be expressed in basal cells of the lungs and its ΔN isoform is recognized as a key player in squamous cell lung cancer. However, the role of p63 in formation and maintenance of bronchial epithelia is largely unknown. The objective of the current study was to determine the expression pattern of the ΔN and TA isoforms of p63 and the role of p63 in the development and maintenance of pseudostratified lung epithelium in situ and in culture. We used a human bronchial epithelial cell line with basal cell characteristics (VA10) to model bronchial epithelium in an air-liquid interface culture (ALI) and performed a lentiviral-based silencing of p63 to characterize the functional and phenotypic consequences of p63 loss. We demonstrate that ΔNp63 is the major isoform in the human lung and its expression was exclusively found in the basal cells lining the basement membrane of the bronchial epithelium. Knockdown of p63 affected proliferation and migration of VA10 cells and facilitated cellular senescence. Expression of p63 is critical for epithelial repair as demonstrated by wound healing assays. Importantly, generation of pseudostratified VA10 epithelium in the ALI setup depended on p63 expression and goblet cell differentiation, which can be induced by IL-13 stimulation, was abolished by the p63 knockdown. After knockdown of p63 in primary bronchial epithelial cells they did not proliferate and showed marked senescence. We conclude that these results strongly implicate p63 in the formation and maintenance of differentiated pseudostratified bronchial epithelium.

Cytologic features of stratified mucin producing intraepithelial lesion of the cervix--a case report

Stratified mucin-producing intraepithelial lesion (SMILE) of the cervix is a human papilloma virus (HPV) associated high grade intraepithelial columnar cell neoplasm that is thought to arise from the reserve cells of the transformation zone. It is composed of immature stratified cells that display intracytoplasmic mucin and is commonly associated with high grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ (AIS), and invasive carcinoma. Here, we describe the cytologic features of SMILE and discuss its pitfalls in cervical cytology. A 51-year-old woman was diagnosed with SMILE on a cervical biopsy. Histologically, the dysplastic epithelium showed enlarged nuclei with increased nuclear density and presence of mucin-producing columnar cells throughout its thickness. The slides from the last two Pap tests (ThinPrep) performed on the patient were reviewed and compared with the histology. Cytologically, groups of atypical endocervical glandular cells were seen on both Pap tests. These groups showed mild nuclear crowding, slightly enlarged nuclei, nuclear hyperchromasia, and indistinct nucleoli. The borders of these cell groups were relatively smooth. Original cytologic diagnosis was atypical squamous cells of undetermined significance (ASC-US) in both instances. HPV (Hybrid Capture 2) testing was positive on both occasions. Similar to the histology, cytologic features of SMILE are subtle. The features are not typical for AIS or for HSIL and could easily be misinterpreted as reactive. This report emphasizes that careful review of crowded groups of glandular cells in HPV positive women is absolutely critical. Based on our knowledge, this is the first description of the cytologic features of these lesions.

Premalignant lesions of the lower female genital tract: cervix, vagina and vulva

Premalignant lesions of the lower female genital tract encompassing the cervix, vagina and vulva are variably common and many, but by no means all, are related to infection by human papillomavirus (HPV). In this review, pathological aspects of the various premalignant lesions are discussed, mainly concentrating on new developments. The value of ancillary studies, mainly immunohistochemical, is discussed at the appropriate points. In the cervix, the terminology and morphological features of premalignant glandular lesions is covered, as is the distinction between adenocarcinoma in situ (AIS) and early invasive adenocarcinoma, which may be very problematic. A spectrum of benign, premalignant and malignant cervical glandular lesions exhibiting gastric differentiation is emerging with lobular endocervical glandular hyperplasia (LEGH), including so-called atypical LEGH, representing a possible precursor of non HPV-related cervical adenocarcinomas exhibiting gastric differentiation; these include the cytologically bland adenoma malignum and the morphologically malignant gastric type adenocarcinoma. Stratified mucin producing intraepithelial lesion (SMILE) is a premalignant cervical lesion with morphological overlap between cervical intraepithelial neoplasia (CIN) and AIS and which is variably regarded as a form of reserve cell dysplasia or stratified AIS. It is now firmly established that there are two distinct types of vulval intraepithelial neoplasia (VIN) with a different pathogenesis, molecular events, morphological features and risk of progression to squamous carcinoma. These comprise a more common HPV-related usual type VIN (also referred to as classic, undifferentiated, basaloid, warty, Bowenoid type) and a more uncommon differentiated (simplex) type which is non-HPV related and which is sometimes associated with lichen sclerosus. The former has a relatively low risk of progression to HPV-related vulval squamous carcinoma and the latter a high risk of progression to non-HPV related vulval squamous carcinoma. Various aspects of vulval Paget's disease are also discussed.

Mixed mucin-producing and squamous differentiated tumor of the uterine cervix: a report of a case as adenosquamous carcinoma in situ

We report a non-invasive mixed mucin-producing and squamous differentiated tumor of the uterine cervix. This tumor was composed of two cell types: mucin-producing cells and non-mucin-producing cells. These cells were intimately mixed with each other, and showed intraepithelial spreading. The mucin-producing cells showed signet-ring or columnar shapes, and were localized to the lower-to-upper epithelial layer. The non-mucin-producing cells had eosinophilic cytoplasms with a monotonous appearance through the epithelium. Mitosis was sometimes observed in both cell types. Immunohistochemically, both cell types were positive for p16(INK4A) . The non-mucin-producing cells were positive for p63 and 34βE12, suggesting squamous differentiation. Although most mucin-producing cells were p63(-) , a few of them were p63(+) and many 34βE12 immunoreactive cells were found in the mucin-producing cells. This tumor was adenosquamous carcinoma in situ.

New developments in endocervical glandular lesions

McCluggage W G (2012) Histopathology New developments in endocervical glandular lesions There is evidence that the prevalence of premalignant and malignant endocervical glandular lesions is increasing in real as well as in apparent terms. In this review, new developments and selected controversial aspects of endocervical glandular lesions are covered, concentrating mainly on premalignant and malignant lesions. The terminology of premalignant endocervical glandular lesions is discussed with a comparison of the World Health Organization classification and the cervical glandular intraepithelial neoplasia (CGIN) system, which is in widespread use in the United Kingdom. Primary cervical adenocarcinomas comprise a heterogeneous group of different morphological types, and while it is known that the majority of these are associated with high-risk human papillomavirus (HPV), it has become clear in recent years that most of the more uncommon morphological types are unassociated with HPV, although they may sometimes be p16-positive. A spectrum of benign, premalignant and malignant cervical glandular lesions exhibiting gastric differentiation is now recognized; these include type A tunnel clusters, typical and atypical lobular endocervical glandular hyperplasia, adenoma malignum and gastric-type adenocarcinoma. The latter is a recently described variant of primary cervical adenocarcinoma which has a different morphological appearance to the usual endocervical type and which is probably associated with different patterns of spread and a worse prognosis. There is accumulating evidence that 'early invasive' cervical adenocarcinomas have an excellent prognosis and are suitable for conservative management. Immunohistochemical markers of value in the distinction between a primary cervical and endometrial adenocarcinoma are discussed. While it is well known that a panel of markers comprising oestrogen receptor (ER), vimentin, p16 and monoclonal carcinoembryonic antigen (CEA) is useful, several major pitfalls are pointed out and this panel of markers is predominantly of value in 'low-grade' adenocarcinomas. A related group of lesions, including cervical ectopic prostatic tissue and vaginal tubulosquamous polyp, are probably derived from para-urethral Skene's glands and may be positive with prostatic markers. Recent developments in cervical neuroendocrine neoplasms are discussed, as these are associated not uncommonly with a premalignant or malignant endocervical glandular lesion.

[Diagnosis and differential diagnosis of cervical adenocarcinoma]

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

Neoplastic Lesions of the Cervix

This review presents a discussion of the gross and microscopic features, diagnosis, differential diagnosis, and prognosis of neoplastic lesions of the cervix. Biomarkers are discussed for each entity presented - cervical intraepithelial neoplasia, squamous carcinoma, glandular neoplasms, adenocarcinoma in situ, adenosquamous carcinoma, and others.

MOLECULAR MARKERS OF EARLY CERVICAL NEOPLASIA

Pure morphological distinction of high-grade squamous intraepithelial lesions (HSILs) from their mimics can be challenging. Diagnosis can be difficult with nonconventional HSILs associated with a metaplastic phenotype, squamous intraepithelial lesions (SILs) that defy precise classification such as "eosinophilic dysplasias", and those that overlap with columnar neoplasms, including stratified variants of adenocarcinoma in situ ("SMILE"). Gene expression and protein profiling have identified biomarkers with the potential to decrease diagnostic variability and increase specificity of histological and cytological analysis. Among the ones clinically useful for HSIL detection are p16(INK4A) and MIB-1 which complement each other, differentiating SIL from normal/atrophic (MIB-1 low) or reactive/immature metaplastic (p16(INK4A) scattered) epithelium. Additional markers, including ProEx(TM) C, have been proposed but their added value is yet to be established. In the final analysis, biomarkers are most helpful for distinguishing benign immature or atrophic proliferations from HSIL. The distinction of LSIL from HSIL must be made on the hematoxylin and eosin-stained section and should be made with care, given the potential consequences of a diagnosis of CIN2 or CIN3.

Diagnostic value and implications of vimentin expression in normal, reactive and neoplastic endocervical epithelium

AIMS

To assess vimentin immunoreactivity in normal, reactive and neoplastic endocervical epithelium, and compare the results with p16 protein, Ki-67 and bcl-2 expression.

METHODS

Sixty-two cervical biopsy specimens including normal endocervical epithelium, tubo-endometrioid metaplasia, adenocarcinoma in situ, stratified mucin producing intraepithelial lesions (SMILE), and invasive adenocarcinomas were stained immunohistochemically for vimentin and for p16 protein, Ki-67 and bcl-2. Twelve cases also included areas of high grade cervical intraepithelial neoplasia (CIN).

RESULTS

Normal endocervical epithelium usually showed subtle but distinct sub-nuclear and delicate lateral cell border vimentin expression while tubo-endometrioid metaplasia exhibited more diffuse cytoplasmic immunoreactivity. Usually adenocarcinoma in situ was completely negative and therefore vimentin staining sharply distinguished the benign and neoplastic epithelial elements. The SMILE lesions and high grade CIN were also vimentin negative in most cases. Most invasive adenocarcinomas were not stained but focal vimentin immunoreactivity was observed in 7/18 cases, and was restricted to small glands and infiltrating cell clusters at the deep (advancing) tumour margin.

CONCLUSIONS

Normal endocervical cells often exhibit vimentin staining, and this is increased in reactive and metaplastic situations, whereas adenocarcinoma in situ is usually completely negative. Therefore vimentin is a useful additional diagnostic marker in the assessment of problematic cervical glandular lesions. The localised re-expression of vimentin at the deep margin of some endocervical adenocarcinomas may be relevant to the process of tumour progression and invasion in these cases.

Cyclin D1 immunoreactivity in normal endocervix and diagnostic value in reactive and neoplastic endocervical lesions

It may be difficult to distinguish reactive glandular lesions from adenocarcinoma in situ of the uterine cervix, and although several immunohistochemical markers have established value in this diagnostic setting, none is completely reliable. We have noted that neoplastic endocervical lesions often show loss of nuclear cyclin D1 expression in contrast to benign glandular cells. Therefore, we investigated cyclin D1 staining in a series of 64 cervical biopsy specimens including examples of normal and reactive endocervical epithelium, adenocarcinoma in situ, stratified mucin-producing intraepithelial lesions, and invasive adenocarcinoma. Thirteen specimens also included a component of high-grade cervical squamous intraepithelial neoplasia. Normal endocervical epithelium usually expressed cyclin D1, although staining was typically focal, and there was increased immunoreactivity in reactive and metaplastic glandular cells including tubo-endometrioid metaplasia. In contrast, most cases of adenocarcinoma in situ were completely negative and, therefore, cyclin D1 staining distinguished benign from neoplastic epithelial cells. Although focal cyclin D1 expression was observed in 5/19 cases of adenocarcinoma in situ, the staining was associated with more marked cytological atypia precluding confusion with a reactive process. The invasive adenocarcinomas were mainly negative for cyclin D1. However, focal staining was observed in 10/19 cases and was mainly restricted to cells at the deep tumor margin, or to small infiltrative glands and detached cell clusters within the stroma. In conclusion, cyclin D1 can be included within an immunohistochemical panel to aid in the distinction between reactive cervical glandular lesions and adenocarcinoma in situ. The localized distribution of staining within invasive lesions suggests that cyclin D1 up-regulation has a specific role during the progression of some endocervical adenocarcinomas.

The expression and diagnostic utility of p63 in the female genital tract

p63 plays a key role in epithelial development in various organs, being expressed in myoepithelial cells and in basal cells of stratified epithelia. In the female genital tract, p63 is expressed in the basal and parabasal cells of mature cervical, vaginal and vulval squamous epithelium, and also in cervical reserve cells at the transformation zone and in immature metaplastic and atrophic cervical squamous epithelium. In this review, the diagnostic utility of p63 immunohistochemical staining in various pathologic scenarios within the female genital tract is discussed. Cervical microglandular hyperplasia is p63 positive with a characteristic subcolumnar location due to expression in reserve cells. There is increased expression in cervical intraepithelial neoplasia, in accordance with the degree of dysplasia. One of the most useful applications of p63 is in the evaluation of problematic cervical carcinomas; most squamous carcinomas exhibit diffuse nuclear immunoreactivity whereas most adenocarcinomas and neuroendocrine carcinomas are negative or focally positive. In conjunction with neuroendocrine markers, p63 is useful in distinguishing between a squamous carcinoma and a small cell or large cell neuroendocrine carcinoma. In the normal endometrium, a population of p63-positive cells is present which may act as a stem cell population and which is increased in various forms of metaplasia. Placental site nodule and epithelioid trophoblastic tumor (lesions derived from chorionic-type intermediate trophoblast) are usually p63 positive whereas placental site reaction and placental site trophoblastic tumor (lesions derived from implantation site intermediate trophoblast) are usually negative; thus, p63 may be useful in the diagnostic algorithm of trophoblastic lesions. p63 positivity in ovarian epithelial tumors is uncommon and largely restricted to squamous and transitional neoplasms, including benign and borderline Brenner tumor. p63 is also positive in cervical transitional metaplasia, Walthard rests, vulval Paget disease secondary to an underlying urothelial malignancy, tubulosquamous polyp of the vagina, and ectopic prostatic tissue in the cervix.

Current concepts in cervical pathology

CONTEXT

The correct diagnosis and reporting of cervical in situ and invasive carcinoma are essential for the appropriate clinical management of patients with human papillomavirus-associated disease.

OBJECTIVES

To review common mistakes made in the diagnosis of cervical dysplasia and invasive carcinoma, describe variants and benign mimics of high-grade squamous intraepithelial lesion and adenocarcinoma in situ, and discuss available ancillary studies that can be useful in making the distinctions as well as to review important factors related to prognosis that should be included in the pathology report.

DATA SOURCES

Review of current literature.

CONCLUSIONS

There are many mimics and variants of cervical squamous and glandular lesions that can be resolved with ancillary studies and careful histologic examination. Prognostically important features, such as tumor size, presence of vascular invasion, and margin status, should always be included in the pathology report.

Immunohistochemistry as a diagnostic aid in cervical pathology

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

Redefining early cervical neoplasia: recent progress

The classification of cervical precancers has evolved over the past 40 years as knowledge concerning the pathogenesis of these human papillomavirus-related lesions has expanded. This commentary reviews the current classification scheme in light of (1) the historical classification systems and (2) the ability of the target epithelium, that is the transformation zone to exhibit varied morphology depending on the cell type that is infected with human papillomavirus. The evolution in our understanding of preinvasive glandular neoplasia is also summarized, with particular attention to so-called superficial (or early) adenocarcinoma in situ. In addition, practical issues in the diagnosis and management of squamous epithelial lesions, particularly the recognition of nonconventional variants and the application of biomarkers, are discussed.

Superficial (early) endocervical adenocarcinoma in situ: a study of 12 cases and comparison to conventional AIS

Although established histologic criteria for the diagnosis of endocervical adenocarcinoma in situ (AIS) have been published, some lesions are not readily classified or present with more subtle degrees of epithelial atypia. Lesions confined to the surface mucosa may be particularly challenging, possibly because they represent early disease. Twelve cases of superficial AIS (SAIS) confined to the surface mucosa or crypt openings culled from the in-house and consultation practices were examined histologically, immunostained for MIB-1 and p16, and analyzed (when possible) for HPV nucleic acids by DNA-DNA in situ hybridization (INFORM). The mean age was 26.7 years for SAIS versus 37.0 years for 42 consecutive cases of conventional AIS from the same practice (P < 0.001). Seven and five were biopsies and conization specimens, respectively. Five coexisted with CIN, four arose in endocervical papillae, and two arose in endocervical polyps. Nuclear hyperchromasia was conspicuous in 10 and mitoses were present in all; however, apoptosis was rare or absent in four, and six exhibited only mild nuclear atypia. Mib-1 staining exceeded 40% in 5 of 7 cases tested, and all (8 of 8) were strongly positive for p16(ink4). Five of five were positive for HPV by ISH with an "integrated" dot-like pattern. SAIS is an early variant of AIS that 1) occurs at a younger mean age, 2) exhibits variable atypia, and 3) arises adjacent to morphologically normal columnar epithelium. Diffuse p16 expression and integrated HPV pattern are identical to that seen in more extensive forms of the disease. Superficial AIS should be suspected in endocervical columnar epithelium with segmental nuclear hyperchromasia with mitotic activity, and confirmed by biomarker staining (p16 and Mib-1) if the pathologist is uncertain of the diagnosis.

p16 expression in the female genital tract and its value in diagnosis

p16 is a cyclin-dependent kinase-4 inhibitor that is expressed in a limited range of normal tissues and tumors. In recent years, immunohistochemistry with p16 antibodies has been used as a diagnostic aid in various scenarios in gynecologic pathology. Diffuse (as opposed to focal) positivity with p16 in the cervix can be regarded as a surrogate marker of the presence of high-risk human papillomavirus (HPV). In cervical squamous lesions, p16 is positive in most high-grade cervical intraepithelial neoplasia (CIN) and in some cases of low-grade CIN, usually those associated with high-risk HPV. p16 may be useful to identify small focal high-grade CIN lesions, to distinguish some cases of CIN involving immature metaplastic squamous epithelium from immature metaplastic squamous epithelium not involved by CIN and to distinguish high-grade CIN from benign mimics. Most cervical carcinomas of squamous, glandular, and small cell type are p16-positive. In cervical glandular lesions, p16 is useful, as part of a panel, in the distinction between adenocarcinoma in situ (diffusely positive) and benign mimics, including tuboendometrial metaplasia and endometriosis, which are usually p16-negative or focally positive. p16 may be used, in combination with other markers, to distinguish between a cervical adenocarcinoma (diffuse positivity) and an endometrioid-type endometrial adenocarcinoma (negative or focally positive). Some uterine serous carcinomas are diffusely positive. In the vulva, p16 is positive in HPV-associated vulval intraepithelial neoplasia (VIN) but negative in VIN not associated with HPV. Similarly, HPV-associated invasive squamous carcinomas are p16-positive, whereas the more common non-HPV-associated neoplasms are largely negative or focally positive. In the uterus, p16 positivity is more common and widespread in leiomyosarcomas than leiomyomas, and this may be a useful aid to diagnosis, although problematic uterine smooth muscle neoplasms have not been extensively studied. Metastatic cervical adenocarcinomas in the ovary are usually diffusely p16-positive, and because these may closely mimic a primary ovarian endometrioid or mucinous adenocarcinoma, this may be a valuable diagnostic aid, although p16 expression in primary ovarian adenocarcinomas of these morphologic subtypes has not been widely investigated. Some ovarian serous carcinomas, similar to their uterine counterparts, are p16-positive.

p63 and p73 do not contribute to p53-mediated lymphoma suppressor activity in vivo

p53 is one of the most important tumor suppressor genes in human cancer, but the roles of its homologues p63 and p73 in tumor suppression, alone or in collaboration with p53, remains controversial. Both p63 and p73 can be deregulated after DNA damage, and induce cell cycle arrest and apoptosis, but mice carrying inactive alleles of these genes do not develop spontaneous tumors. Since heterozygous loss of p53 confers strong sensitization to radiation-induced lymphoma development, we investigated the possibility that radiation exposure may reveal previously undetected tumor suppressor properties in p63 or p73, alone or in combination with p53. Animals heterozygous for p63 or p73, as well as both double heterozygous p53/p63 or p53/p73 mice, showed no significant differences in tumor latency, spectrum or frequency after gamma-radiation, compared to their control counterparts. Deletions were found near the p63 locus on chromosome 16 in radiation-induced tumors, but these frequently included the knockout allele. No deletions or LOH involving the p73 gene were detected, and expression of both genes was maintained in the tumors. We conclude that p53 homologues do not contribute to p53 tumor suppressor activity in lymphoma development.

The pathology and management of endocervical glandular neoplasia

The incidence of cervical glandular intraepithelial neoplasia and adenocarcinoma is rising, and our limited knowledge about these lesions presents the gynecologist with a management dilemma. Recently, pathologists have paid increasing attention to the diagnosis and pathogenesis of adenocarcinoma of the cervix. Although there is no uniformity in the management of these lesions, nonradical surgery appears to give satisfactory results especially in young women who want to preserve their fertility. This review focuses on the issues surrounding the histologic diagnosis of endocervical glandular abnormalities, including their classification, and discusses the management of cervical preinvasive glandular disease, including follow-up after treatment.

Microglandular hyperplasia: a model for the de novo emergence and evolution of endocervical reserve cells

BACKGROUND

Microglandular hyperplasia (MGH) of the cervix in human beings is associated early with gland proliferation and terminates in mature squamous metaplasia. Using antibodies to basal cell markers, we analyzed biopsies with MGH to profile the distribution and evolution of reserve cells and their relationship to these epithelial components.

DESIGN

Serial sections of 24 MGHs were subdivided into (1) early MGH with microacinar proliferation, abundant subnuclear vacuoles, and a paucity of supporting stroma and (2) late MGH with more prominent supporting stroma and/or squamous metaplasia. Serial sections were stained with antibodies to p63, bcl-2, and keratin-5.

RESULTS

Three patterns of p63 staining were observed corresponding to the age of the MGH: (1) scattered staining of columnar cells, (2) focal subcolumnar staining in a reserve cell distribution, and (3) linear subcolumnar arrays of p63-positive reserve cells that in some MGHs expanded into a squamous metaplasia. Early acinar proliferations showed weak and focal columnar cell staining followed by focal subcolumnar p63-positive cells. In late lesions, p63 staining was compartmentalized to the extraglandular (or subcolumnar) areas. Stainings of p63, bcl-2, and keratin-5 were concordant. Staining for keratin 14, which localizes to squamous cells, was variable.

CONCLUSIONS

The immunohistochemical profile in MGH indicates that reserve cells are created in adulthood during specialized columnar proliferations. This columnar to reserve cell transition may produce a stable population of reserve cells or a transition to squamous metaplasia. Similar patterns are seen in cervical neoplasia, suggesting a link between benign and neoplastic cervical epithelial differentiation.

Critical role of p63 in the development of a normal esophageal and tracheobronchial epithelium

The trachea and esophagus originate from the foregut endoderm during early embryonic development. Their epithelia undergo a series of changes involving the differentiation of stem cells into unique cell types and ultimately forming the mature epithelia. In this study, we monitored the expression of p63 in the esophagus and the trachea during development and examined in detail morphogenesis in p63(-/-) mice. At embryonic day 15.5 (E15.5), the esophageal and tracheobronchial epithelia contain two to three layers of cells; however, only the progenitor cells express p63. These progenitor cells differentiate first into ciliated cells (p63(-)/beta-tubulin IV(+)) and after birth into mature basal cells (p63(+)/K14(+)/K5(+)/BS-I-B4(+)). In the adult pseudostratified, columnar tracheal epithelium, K14(+)/K5(+)/BS-I-B4(+) basal cells stain most intensely for p63, whereas ciliated and mucosecretory cells are negative. In stratified squamous esophageal epithelium and during squamous metaplasia in the trachea, cells in the basal layer stain strongest for p63, whereas p63 staining declines progressively in transient amplifying and squamous differentiated cells. Generally, p63 expression is restricted to human squamous cell carcinomas, and adenocarcinomas and Barrett's metaplasia do not stain for p63. Examination of morphogenesis in newborn p63(-/-) mice showed an abnormal persistence of ciliated cells in the esophagus. Significantly, in both tissues, lack of p63 expression results in the development of a highly ordered, columnar ciliated epithelium deficient in basal cells. These observations indicate that p63 plays a critical role in the development of normal esophageal and tracheobronchial epithelia and appears to control the commitment of early stem cells into basal cell progeny and the maintenance of basal cells.

TP53 family members and human cancers

Based on gene sequence homologies, a p53 (TP53) gene family become apparent with the addition of the most recently identified p63 (TP73L; formerly TP63) and p73 (TP73) genes to the already known p53. The p53 gene encodes for a unique protein eliciting well-known tumor suppressor gene (TSG) properties that mediate cellular response to DNA damage, e.g., cell cycle arrest or apoptosis. In contrast, both homologues specify an array of isoforms different in their N- and C-terminal domains. Transactivating isoforms, such as TAp63/p73, show TSG properties similar to p53, while isoforms lacking N-terminal transactivating domain such as DeltaNp63/p73, induce a functional block against p53 as well as TAp63/p73 activities. Both p63/p73 types of isoforms are involved in development: p63 is critical for epithelial stem cell renewal and epithelial homeostasis, and p73 is involved in neurogenesis and natural immune response. These facts support interdependent functions for the p53 family members, which appear linked together in a complex and tight regulation network to fulfill cellular functions related to DNA damage and tissue homeostasis maintenance. The lack of p63/p73 mutations in human cancers rule out a typical TSG role for either of the p53 homologues. Nonetheless, p63 and p73 genes seem strongly involved in malignancy acquisition and maintenance process because of: 1) their tissue identities, and 2) their close interplay activities within the p53 family members, and primarily through the negative regulatory role played by DeltaNp63/p73 isoforms for cell death control and differentiation.

Endocervical glandular lesions: controversial aspects and ancillary techniques

The incidence of malignant and premalignant endocervical glandular lesions is increasing. This review covers controversial and difficult aspects regarding the categorisation and diagnosis of these lesions. The terminology of premalignant endocervical glandular lesions is discussed because of the differences between the UK terminology and the widely used World Health Organisation classification. The morphology and histological subtypes of premalignant endocervical glandular lesions are described. Early invasive adenocarcinoma and difficulties in the diagnosis and recognition of this entity are covered, as is the measurement of early invasion within cervical adenocarcinoma. Several benign endocervical glandular lesions can mimic malignant and premalignant endocervical glandular lesions, and the distinction of these benign mimics from premalignant and malignant lesions using ancillary immunohistochemical studies is also covered. Antibodies used to distinguish between endometrial and endocervical adenocarcinoma, in the diagnosis of cervical minimal deviation adenocarcinoma of mucinous type (adenoma malignum), and in the diagnosis of cervical mesonephric lesions are also reviewed.

Symposium part 1: Should the Bethesda System terminology be used in diagnostic surgical pathology?: Point

During the past 50 years, the histologic classification of cervical intraepithelial neoplasia (CIN) has evolved to incorporate the entire spectrum of genital papillomavirus infections, segregating those lesions with the higher risk of containing prototypic high-risk human papillomavirus types, and recently has meshed with treatment algorithms that include loop electrical excision procedures and follow-up alone. This review describes a classification system that divides CIN into categories of low-grade (CIN 1) and high-grade (CIN 2 and CIN 3). To successfully apply this system, the practitioner must efficiently exclude nonneoplastic entities and base the distinction of CIN 1 from CIN 2/3 on criteria that recognize the effects of viral oncogenes on replicating cells. This is achieved by basing the diagnosis of CIN 1 on uniform polarized epithelial growth, low mitotic index, low mitotic counts, and minimal parabasal cell anisokaryosis and coarse chromatin and CIN 2 on the presence of these features or abnormal mitoses. Simply put, the definition of CIN 2 (or higher) is the presence of atypical immature cells in the biopsy that if seen in a cytologic smear would merit a diagnosis of high-grade squamous intraepithelial lesion. In essence, a successful two-grade system requires careful application of cytologic criteria in a histologic milieu. This model is illustrated in a set of 25 images that underscore the importance of excluding benign changes (with the appropriate use of biomarkers), segregating unusual variants of low-grade squamous intraepithelial lesions, and identifying the morphologic transition to high-grade squamous intraepithelial lesions (CIN 2 or CIN 3) with an acceptable level of reproducibility.

Symposium part IV: investigative approaches to endocervical pathology

There is continuing interest in the study of adenocarcinoma of the cervix and its precursors because of its increase in incidence, both absolute and relative, to squamous neoplasia and the complexity of benign glandular lesions with which endocervical neoplasia may be confused. Investigative techniques may be applied as aids to diagnosis, as prognostic markers, and to further our understanding of etiopathogenesis. This article focuses on recent developments in the four areas of epithelial glycoproteins, molecular markers, cell proliferation markers, and human papillomaviruses as applied to endocervical pathology. Although immunohistochemistry remains dominant, a wide range of other techniques is discussed.

Loss of p63 expression is associated with tumor progression in bladder cancer

p63, a member of the p53 gene family, encodes multiple proteins that may either transactivate p53 responsive genes (TAp63) or act as a dominant-negative factor toward p53 and p73 (Delta Np63). p63 is expressed in many epithelial compartments and p63(-/-) mice fail to develop skin, prostate, and mammary glands among other defects. It has been previously shown that p63 is expressed in normal urothelium. This study reports that p63 is regulated in bladder carcinogenesis and that p63 expression is lost in most invasive cancers whereas papillary superficial tumors maintain p63 expression. Examination of bladder carcinoma cell lines reveals that certain lines derived from invasive carcinomas maintain expression of Delta Np63, as demonstrated by both immunoblotting and confirmed by isoform-specific quantitative reverse transcriptase-polymerase chain reaction. Another novel finding reported in this study is the fact that p63(-/-) mice develop a bladder mucosa epithelial layer yet fail to complete uroepithelial differentiation, producing a nontransitional default cuboidal epithelium. These data indicate that in contrast to the skin and prostate, p63 is not required for formation of a bladder epithelium but is indispensable for the specific differentiation of a transitional urothelium.

p63 immunoreactivity in lung cancer: yet another player in the development of squamous cell carcinomas?

The p63 protein, a member of the p53 family of nuclear transcription factors, is characterized by different capabilities of transactivating reporter genes, inducing apoptosis, and functioning as dominant-negative agent. This study evaluated the prevalence and prognostic implications of p63 immunoreactivity in 221 patients with stage I non-small cell lung carcinoma (NSCLC) and in 57 patients with stage I-IV neuroendocrine tumours (NET). The results were correlated with the tumour proliferative fraction, the accumulation of p53 protein, and with patient survival. p63 immunoreactivity was seen in 109/118 squamous cell carcinomas, 15/95 adenocarcinomas, 2/2 adenosquamous carcinomas, 4/6 large cell carcinomas, 9/20 poorly differentiated NET, and 1/37 typical and atypical carcinoids (p < 0.001). Furthermore, the prevalence of p63-immunoreactive cells increased progressively from pre-neoplastic and pre-invasive lesions to invasive squamous cell carcinomas. In these latter tumours, but not in adenocarcinomas, p63 immunoreactivity correlated directly with the tumour proliferative fraction (p = 0.028), and inversely with the tumour grade (p = 0.004). No relationship was found with p53 protein immunoreactivity or the other clinico-pathological variables examined. Although p63 is likely to be involved in the development of pulmonary squamous cell carcinoma, it does not carry any prognostic implication for NSCLC patients.

Expression of p53-related protein p63 in the gastrointestinal tract and in esophageal metaplastic and neoplastic disorders

p63 is a p53-related DNA-binding protein that helps regulate differentiation and proliferation in epithelial progenitor cells. Its expression has never been evaluated in the human gastrointestinal tract. The aim of this study was to evaluate the expression of p63 in the esophagus and related metaplastic and neoplastic disorders to gain insight into the pathogenesis of these processes. Of particular interest was the expression of p63 in Barrett esophagus (BE) and in BE-associated multilayered epithelium. Multilayered epithelium has been postulated to represent an early precursor to the development of BE primarily because it shares morphologic and immunophenotypic features of both squamous and columnar epithelium, and has been shown prospectively to be highly associated with BE. Routinely processed mucosal biopsy or resection specimens that contained normal esophageal squamous epithelium (n = 20), squamous dysplasia (n = 4), squamous cell carcinoma (n = 7), BE (n = 10), BE-associated multilayered epithelium (n = 13), esophageal mucosal gland ducts (n = 10), BE-associated dysplasia (n = 12), and BE-associated adenocarcinoma (n = 7) were immunostained for p63 to determine the extent and location of staining. p63 staining was compared with the staining patterns observed for p53, Ki 67 (proliferation marker), and cytokeratins (CKs) 13 (squamous marker), 14 (basal squamous marker), 8/18 (columnar marker), and 19 (basal/columnar marker). Expression of p63 messenger RNA (mRNA) isoforms was also analyzed by reverse-transcription polymerase chain reaction of freshly isolated tissues. In the normal esophagus, p63 was expressed in the basal and suprabasal layers of the squamous epithelium and in basal cells that line the mucosal gland ducts but was negative in all other epithelia of the gastrointestinal tract, including the stomach, small intestine, and colon. Similarly, p63 was not expressed in BE, but it, was present in the basal layer of multilayered epithelium in 9 of 13 cases (69%). p63-positive cells in multilayered epithelium and in the mucosal gland duct epithelium were positive for CK8/18 (100%) and CK13 (67% and 30%, respectively) and negative for CK14 (0%), in contrast to p63-positive cells in squamous epithelium, which were positive for CK14 and CK13 (100%) but negative for CK8/18. In neoplastic tissues, p63 was diffusely expressed in all cases of esophageal squamous cell dysplasia and carcinoma but was negative in all cases of esophageal and colorectal adenocarcinoma. The DeltaN isoform of p63 mRNA predominated in all benign and neoplastic squamous tissues examined. p63 may represent a marker of 2 distinct epithelial progenitor cells (basal squamous epithelium and gland duct epithelium) in the esophagus. P63 is upregulated in squamous neoplastic conditions and in this manner may play a role in squamous carcinogenesis. These data also indicate that multilayered epithelium is phenotypically similar to, and may share a lineage relationship with, mucosal gland duct epithelium.

Histologic and immunophenotypic classification of cervical carcinomas by expression of the p53 homologue p63: a study of 250 cases

Recent studies of the p53 homologue p63 indicate that this gene is preferentially expressed in basal and immature cervical squamous epithelium. This study correlated p63 expression with morphologic phenotype and human papillomavirus (HPV) type in a wide range of cervical neoplasms. Two hundred fifty cases of cervical carcinoma, including squamous cell carcinoma (SCCA; n = 178), adenocarcinoma (ADCA; n = 28), adenosquamous carcinoma (ASCA; n = 8), neuroendocrine carcinoma (NECA; n = 15), and other variant or mixed types (n = 21) were studied. Ninety-seven percent of SCCA, 0% of ADCA, and 0% of SCUC showed strong (>75% v <30%) positivity for p63 (P<.001). p63 sharply distinguished SCCA (p63+) from ADCA (p63-), Large-cell, poorly differentiated carcinomas were distinguished as putative glandular (glassy cell) or squamous (lymphoepithelial-like or spindle cell) types based on p63 staining. Eight (73%) of 11 neuroendocrine tumors tested were chromogranin positive; all showed no or low (<30%) levels of p63 immunostaining. Absence of p63 was also associated with a subset of nonneuroendocrine undifferentiated carcinomas. Transitions from squamous to columnar or undifferentiated morphology coincided with loss of p63 expression. A strong association between HPV 16 and p63 positivity was identified because of the colocalization of both within tumors of squamous phenotype. p63 is a powerful marker for squamous differentiation and, when diffusely expressed, excludes a glandular or neuroendocrine differentiation. p63 may be useful for differentiating pure squamous or glandular from adenosquamous carcinomas, tracking shifts in differentiation within tumors, supporting (by its absence) the diagnosis of neuroendocrine carcinomas, and clarifying the spectrum of poorly differentiated carcinomas lacking either squamous or neuroendocrine differentiation.

Expression of the p53 homologue p63 in early cervical neoplasia

BACKGROUND

p63, a homologue of the tumor suppressor gene p53, is expressed in embryonic, adult murine, and human basal squamous epithelium and encodes both transactivating and dominant negative transcript isoforms. Mouse embryos functionally deficient in p63 fail to replenish basal squamous epithelial cells, resulting in multiple defects that include absent genital squamous epithelium. This study investigated the expression of p63 in the human cervical transformation zone and early cervical neoplasia.

METHODS

Tissue localization of p63 was determined by immunohistochemistry in a wide range of epithelia. A correlation was also made between p63 expression and squamous basal cell (keratin 14), endocervical columnar cell (mucicarmine), and cell-cycle specific (Ki-67) markers.

RESULTS

p63 expression by immunostaining delineated basal and parabasal cells of maturing ectocervical squamous mucosa, squamous metaplasia in the cervix, and basal and subcolumnar cells of the cervical transformation zone. In atrophic epithelia immunostaining for p63 was present in all cell strata. In early cervical neoplasia, p63 expression was inversely correlated with both squamous cell maturation and nonsquamous differentiation in CIN. This biomarker also identified basal cells in a subset of preinvasive cervical neoplasms with endocervical cell differentiation that were bcl-2 and keratin 14 negative.

CONCLUSIONS

In the lower female genital tract, p63 is preferentially expressed in immature cells of squamous lineage and is not linked to cell proliferation. The broader range of p63 expression relevant to keratin 14 and bcl-2 indicates that p63 may identify additional subsets of benign and neoplastic epithelial basal cells in the cervical transformation zone and may be useful in studying cell differentiation in the early stages of neoplastic change in this region.