Pagetoid bowen disease: a report of 2 cases that express cytokeratin 7

Nipple Lesions of the Breast: An Update on Morphologic Features, Immunohistochemical Findings and Differential Diagnosis

Because of the unique anatomic structure of the nipple, a few specific breast lesions occur only at this site. Large lactiferous sinuses may be involved by inflammatory conditions such as squamous metaplasia of lactiferous ducts and ductal ectasia or be the site of uncommon superficial epithelial neoplasms such as nipple adenoma or syringomatous tumor of the nipple. Paget disease of the nipple may be secondary to intraepidermal extension of ductal carcinoma in situ in the underlying lactiferous ducts or develop from malignant transformation of Toker cells. Invasive breast cancer may also arise primarily in the nipple. Most of these conditions present as a palpable mass and/or skin changes with or without nipple discharge. Due to the delicate location and often relatively small size of nipple lesions, biopsy specimens are often superficial and fragmented, and the interpretation is challenging. Knowledge of the morphologic and immunophenotypic features of nipple lesions is essential in making the correct diagnosis. Information on the molecular alterations underpinning nipple neoplasms is currently very limited.

British Association of Dermatologists guidelines for the management of people with cutaneous squamous cell carcinoma in situ (Bowen disease) 2022

The overall objective of the guideline is to provide up-to-date, evidence-based recommendations for the management of squamous cell carcinoma in situ (SCC in situ). The document aims to: offer an appraisal of all relevant literature up to 13th August 2021, focusing on any key developments; address important, practical clinical questions relating to the primary guideline objective; provide guideline recommendations and if appropriate research recommendations.

Extramammary Paget's Disease of the Vulva and Concomitant Premalignant/Malignant Vulvar Lesions: A Potential Challenge in Diagnosis and Treatment

The aim of the present study was to evaluate the incidence of concomitant vulvar cancers or premalignant lesions in women surgically treated for extramammary Paget's disease of the vulva (EMPDV) through a multicenter case series. The medical records of all women diagnosed with and treated for EMPDV from January 2010 to December 2020 were retrospectively analyzed. Women with EMPDV and synchronous vulvar cancer, vulvar intraepithelial neoplasia (VIN) and/or lichen sclerosus (LS) at the histology report were included in the study. A total of 69 women eligible for the present study were considered. Concomitant vulvar lesions occurred in 22 cases (31.9%). A total of 11 cases of synchronous VIN (50%) and 14 cases (63.6%) of concomitant LS were observed. One patient (4.5%) had synchronous vulvar SCC (FIGO stage 1B). Women with EMPDV and concomitant premalignant/malignant vulvar lesions had a significantly higher rate of invasive EMPDV and wider lesions with an extravulvar involvement. The specific meaning of the association between EMPDV, VIN, SCC and LS remains unclear. The potential overlapping features between different vulvar lesions highlight the importance of dedicated gynecologists and pathologists in referral centers.

Differentiating pagetoid Bowen disease from Paget disease on the nipple-areola complex: Two unique, challenging cases

Pagetoid Bowen disease is a subtype of Bowen disease that accounts for 5% of Bowen disease. It is extremely rare for Bowen disease to appear on the nipple-areola complex, with only seven cases described in the previous literature. Of those seven cases, only one was of the pagetoid subtype. We report two cases of pagetoid Bowen disease on this location, one of them being the first case of pagetoid Bowen disease affecting the nipple reported to date. On this location, it is crucial to perform a meticulous differential diagnosis to rule out Paget disease, because of its contrasting therapeutic and prognostic implications. In order to do this, clinical and histopathological aspects must be considered. From a clinical point of view, previous literature has stated that nipple involvement can be a clue that points to Paget disease. However, one of our cases shows that this is not always true. Regarding histopathological analysis, a complete excision of the tumor might be necessary to observe clear features of Bowen disease, such as full-thickness atypia of the epidermis and intercellular bridges. An immunohistochemical panel comprising carcinoembryonic antigen, gross cystic disease fluid protein, epithelial membrane antigen, p63, CK34betaE12, periodic acid-Schiff, estrogen receptor, and progesterone receptor can be decisive in complicated cases.

[Pathology of the nipple-areola complex : I. Paget's disease of the nipple, variants, and differential diagnoses]

The classical Paget's disease of the nipple is histologically characterized by tumor cell infiltration originating in intraductal or invasive breast carcinoma, immunohistologically by a frequent overexpression of HER2 and clinically by eczema-like changes of the nipple and areola. Variants with different histological, immunohistological, and clinical features are observed in nonclassical forms of Paget's disease, such as isolated Paget's disease of the nipple, anaplastic Paget's disease, Paget's disease with invasion, and pigmented Paget's disease of the nipple. In the differential diagnosis of Paget's disease, benign changes have to be considered, including Toker cell hyperplasia, nipple eczema, and rare dermatoses.

A challenging case of pigmented Bowen's disease and differential diagnosis of pagetoid pigmented skin lesions

Differentiation of pagetoid cutaneous neoplasms can be very challenging on hematoxylin and eosin-stained sections.

We report a singular case of pigmented pagetoid Bowen’s disease showing transitional features between extramammary Paget’s disease and in situ squamous cell carcinoma.

Treatment Effects Can Mimic Recurrent Extramammary Paget Disease in Perianal Skin

The histologic differential diagnosis of perianal Paget disease includes malignant melanoma, pagetoid spread of squamous cell carcinoma, and secondary involvement by colorectal carcinoma. While consideration of these entities is useful when establishing a diagnosis, it does not apply when patients with Paget disease undergo surveillance for recurrent disease. Treatment of perianal Paget disease consists of a combination of surgical excision with skin grafts and topical chemotherapeutic agents that induce cytologic alterations in benign cells and simulate recurrent malignancy. To evaluate the therapy-related changes and possible diagnostic pitfalls in patients with Paget disease, we reviewed 412 posttreatment tissue samples from 3 women with primary perianal Paget disease who underwent wide excision, skin grafting, and topical 5-fluorouracil therapy. Biopsy samples from engrafted skin often displayed single and clustered cells with hyperchromatic nuclei dispersed in the deep epidermis. Similar cells were scattered throughout all levels of the epidermis in biopsy samples following topical chemotherapy. The abnormal cells were negative for cytokeratin 7 (CK7) and mucicarmine in both situations. Disease ultimately recurred in all patients; some Paget cells showed classic features with eosinophilic or mucinous cytoplasm and eccentric nuclei, whereas others were smaller with less conspicuous atypia. All Paget cells showed strong, membranous CK7 staining. In short, treatment of perianal Paget disease can elicit cytologic abnormalities in benign epithelial cells that simulate the cytologic features of recurrent disease, and can diminish the atypia of Paget cells. Immunohistochemical stains for CK7 can be helpful when evaluating surveillance samples from these patients.

Pagetoid Bowen Disease Initially Misdiagnosed as Ectopic Extramammary Paget's Disease

Pagetoid Bowen disease is a histological variant of Bowen disease which demonstrates large pale staining cells (pagetoid cells). It requires differential diagnosis from other cutaneous malignancies with similar patterns, such as extramammary Paget's disease (EMPD) and Pagetoid melanoma in situ. Herein, we report a case of Pagetoid Bowen disease which was initially misdiagnosed as ectopic EMPD.

Ultrastructural Examination of a Case of Pagetoid Bowen Disease Exhibiting Immunohistochemical Features in Common With Extramammary Paget Disease

A panel of immunohistochemical markers may be used to differentiate between pagetoid Bowen disease (PBD) and primary extramammary Paget disease (EMPD) in selected cases. Although diffuse staining with cytokeratin 7 (CK7), CAM5.2, carcinoembryonic antigen, epithelial membrane antigen (EMA), and gross cystic disease fluid protein 15 generally supports diagnosis of EMPD, cases have been reported where PBD also expressed CK7, EMA, and CAM5.2. Based on these findings, some authors suggested that the 2 entities may arise from the same multipotent stem cell, capable of further differentiation toward squamous and secretory lines. To the best of our knowledge, this issue has never been investigated by comparing PBD and EMPD at the ultrastructural level. We performed the first ultrastructural study of a case of PBD exhibiting common immunohistochemical features with EMPD. The lesion displayed some ultrastructural features often observed in Bowen disease and some that are typically found in EMPD. These findings indicate the presence of a bidirectional differentiation--secretory and squamous--within the same lesion, thus supporting the hypothesis that PBD and primary EMPD may arise from a common progenitor cell.

Immunohistochemistry in dermatopathology

CONTEXT

Immunohistochemistry is not a diagnostic test but a highly valuable tool that requires interpretation within a context.

OBJECTIVE

To review the current status and limitations of immunohistochemistry in dermatopathology.

DATA SOURCES

English-language literature published between 1980 and 2014.

CONCLUSIONS

Although immunohistochemistry is rarely completely specific or sensitive, it is an important adjunctive technique in dermatopathology and can be helpful in a series of diagnostic dilemmas.

Diagnostic utility of p63 expression in the differential diagnosis of pagetoid squamous cell carcinoma in situ and extramammary Paget disease: a histopathologic study of 70 cases

Pagetoid squamous cell carcinoma in situ (PSCCIS) is characterized by cytologically atypical cells, with abundant, pale-staining cytoplasm arranged singly and in nests within the epidermis (pagetoid distribution). The growth pattern of PSCCIS may simulate extramammary Paget disease (EMPD), and in some cases, it is difficult to differentiate the 2 entities based on histomorphology alone. In this study, biopsy samples from 30 cases of PSCCIS and 40 cases of primary EMPD were examined using immunohistochemical staining for p63. In cases where the boundaries between the pagetoid cells and surrounding keratinocytes were difficult to assess, an eosin counterstain was applied to highlight the cytoplasm of the lesional cells. The immunohistochemical results were analyzed using Fisher exact test. The results showed that all 30 cases of PSCCIS exhibited strong nuclear positivity for p63 in the neoplastic cells, when compared with 0 of 40 cases of primary EMPD (P < 0.0001). In summary, p63 is a useful marker in differentiating PSCCIS from primary EMPD. The authors propose the addition of p63 immunostain in the panel of markers when evaluating pagetoid cutaneous neoplasms.

Expression of CK7, Cam 5.2 and Ber-Ep4 in cutaneous squamous cell carcinoma

BACKGROUND

Cytokeratin 7 (CK7) and Cam 5.2 are often used to differentiate extramammary Paget's disease (EPD) from squamous cell carcinoma (SCC) in situ because they are generally considered to be expressed in the former but not in the latter. However, we have encountered CK7+ and Cam 5.2+ SCCs.

METHODS

We evaluated CK7, Cam 5.2 and Ber-Ep4 expression in SCC and EPD.

RESULTS

We found significant CK7 and Cam 5.2 positivity in SCCs, particularly in those with a pagetoid pattern. Only one case expressed Ber-Ep4.

CONCLUSIONS

We conclude that CK7 and Cam 5.2 expression may occur in SCC. A panel including Ber-Ep4 is advisable for immunohistochemical differentiation of EPD from SCC.

Extramammary Paget's Disease of External Genitalia with Bowenoid Features

Extramammary Paget's disease (EMPD) is an uncommon intraepithelial adenocarcinoma, primarily affecting the apocrine-bearing skin. Bowen disease is an intraepithelial squamous cell carcinoma having the potential to become invasive carcinoma. The histopathological concomitant features between EMPD and Bowen disease have been described. One theory is that primary EMPD arises multicentrically, within the epidermis from the pluripotent stem cells. Herein, we describe a case of EMPD that had bowenoid features, and review the previous cases associated with the origin of EMPD.

Prostate carcinoma metastatic to the skin as an extrammamary Paget's disease

AIM

The current paper describes a case of prostatic adenocarcinoma metastatic to the skin presenting as an extrammamary Paget's disease, a very rare and poorly characterised morphological entity. We report a case of prostatic carcinoma metastatic to skin showing a pattern of extramammary Paget's disease which has not been clearly illustrated in the literature Case presentation: A 63 year-old man with prostatic adenocarcinoma developed cutaneous metastases after 16 years. The inguinal metastases were sessile and 'keratotic.' The tumour displayed solid, glandular areas as well as a polypoid region suggestive of extramammary Paget's disease were identified.

DISCUSSION AND CONCLUSIONS

We review the diagnostic criteria that have led to the correct histopathological diagnosis in this case. A differential diagnosis of the pagetoid spread in the skin and various forms of cutaneous metastases determined by a prostatic adenocarcinoma as well as the role of immunohistochemistry in establishing the prostatic origin are presented in the context of this case. Although, morphologically the cells presented in the skin deposits were not characteristic for adenocarcinoma of prostate, immunohistochemistry for PSA and PSAP suggested a prostatic origin.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1395450057455276.

Primary Extramammary Paget's Disease Combined with Bowen's Disease in Vulva

Extramammary Paget's disease (EMPD) is a uncommon neoplastic condition of apocrine gland-bearing skin and its occurrence in combination with Bowen's disease is very rare. The most common site of involvement is the vulva, although perineal, perianal, scrotal and penile skin may also be affected. EMPD is usually not combined with Bowen's disease. We report an interesting case of EMPD combined with Bowen's disease, which was confirmed by immunohistochemical stain.

Acantholytic Anaplastic Extramammary Paget's Disease: A Case Report and Review of the Literature

Extramammary Paget's disease (EMPD) is an uncommon intraepithelial neoplasm that most commonly arises on the vulva and perianal region. Very few cases of EMPD revealing a histological Bowenoid appearance have been reported. This study describes scrotal EMPD presenting with histological features of Bowen's disease in a 79-year-old man. He presented with a 5-year history of a pruritic erythematous plaque and a verrucous papule on the scrotum. The verrucous papule histopathologically showed Bowenoid features, and the erythematous plaque demonstrated acantholytic EMPD. Immunohistochemical findings revealed strong expression for carcinoembryonic antigen, Cam 5.2, epithelial membrane antigen, cytokeratin (CK) 7, and pancytokeratin (AE1/AE3) in both areas, but negative CK20 staining, supporting the overall diagnosis of primary acantholytic anaplastic EMPD. This is the first reported case of acantholytic anaplastic EMPD in the Korean literature.

Cystic fibrosis transmembrane conductance regulator is helpful in the distinction of extra-mammary Paget's disease from squamous cell carcinoma in situ (Bowen's disease)

Cystic fibrosis transmembrane conductance regulator (CFTR) represents a cAMP-dependent channel found in normal apocrine glands. The classification and histogenesis of extra-mammary Paget's disease (EMPD) remains controversial, but it is generally accepted that primary EMPD exhibits apocrine differentiation. Therefore, we examined the utility of CFTR in the differential diagnosis of EMPD and squamous cell carcinoma in situ (SCCIS). Twenty-five cases of SCCIS and 14 cases of EMPD were evaluated for immunohistochemical expression of CFTR. Expression was scored as 0 (<5% of cells positive), 1+ (5-75% of cells positive) or 2+ (>75% cells positive). Twenty-three of 25 cases of SCCIS showed no reactivity for CFTR, and the remaining 2 cases showed 1+ staining. Thirteen of 14 cases of EMPD showed 2+ staining, while 1 case showed 1+ staining. We recognize that the pathological appearance along with clinical history and site of occurrence are sufficient to distinguish EMPD and SCCIS in most instances. However, distinction between the two can become more challenging when the location and histopathology are not characteristic. We conclude that when an immunohistochemical panel is diagnostically necessary, the expression of CFTR favors a diagnosis of EMPD over SCCIS.

Lesions of anogenital mammary-like glands: an update

Long considered to be ectopic breast tissue representing the caudal remnants of the milk ridges, anogenital mammary-like glands are nowadays thought to represent a normal constituent of the anogenital area. Lesions involving these glands, benign or malignant, epithelial or stromal manifest a striking similarity to their mammary counterparts. This review addresses the recent literature on lesions of anogenital mammary-like glands and our personal experience with various lesions related to these structures. Discussed are the normal anatomy and histology of these glands as well as the clinical presentation, histopathological and immunohistochemical features, molecular biological aspects, and differential diagnosis of various lesions involving anogenital mammary-like glands, including lactating adenoma, hidradenoma papilliferum, hidradenocarcinoma papilliferum, fibroadenomas, phyllodes tumor, pseudoangiomatous stromal hyperplasia, extramammary Paget disease, and other carcinomas. In addition, "nonspecific" epithelial or stromal changes some of which can be likened to similar changes occurring in a range of benign breast disease, including sclerosing adenosis, columnar cell lesions, ductal lesions and various metaplastic changes affecting epithelium and myoepithelium are discussed. Although lesions of anogenital mammary-like glands are often discussed in many dermatopathology textbooks in the context of cutaneous adnexal neoplasms we advocate that the best approach to the diagnosis of these lesions is to relate them to analogous well recognized lesions occurring in the breast, that is, through the eyes of a breast pathologist. This will enable their recognition, precise classification and should introduce greater uniformity in how they are reported in the literature so that more meaningful clinicopathological comparisons and correlations may be made.

Frequent expression of the breast differentiation antigen NY-BR-1 in mammary and extramammary Paget's disease

While mammary Paget's disease (MPD) is clearly linked to breast cancer, the histogenesis of extramammary Paget's disease (EMPD) is controversial. Recently NY-BR-1, a differentiation antigen expressed in the breast and in skin adnexal structures was identified. Its protein expression is restricted to normal and neoplastic breast epithelium and to adnexal tumors of the skin. In this study, we examine NY-BR-1 expression by immunohistochemistry in 24 MPD cases with synchronous ductal carcinoma in situ or invasive breast cancer. Results were compared with 26 cases of EMPD of men (n= 4) and women (n= 22) as well as in apoeccrine glands of the axilla and mammary-like glands of the anogenital region. We found NY-BR-1 positivity in 18 of 24 MPD (75%) and in 21 of 26 EMPD (80.8%). All apoeccrine glands of the axilla and mammary-like glands of the anogenital region were NY-BR-1-positive. NY-BR-1 expression is a common finding in MPD and in EMPD. When considering the diagnosis of Paget's disease, NY-BR-1 is a useful diagnostic marker. Furthermore NY-BR-1 positivity in apoeccrine glands of the axilla and anogenital region suggests a potential histogenetic link between these structures and Paget's disease.

Mucin immunohistochemistry in the diagnosis and mapping of extramammary Paget's disease

Extramammary Paget's disease (EMPD) is a rare skin cancer of the genital region in which cancer cells with enlarged nuclei and pale cytoplasm are scattered singly in the affected epidermis. These cancer cells, called Paget cells, contain mucin, which is never found in normal epidermis. The oligosaccharide side chains of Paget cell mucin end with sialic acid. Sialic acid is easily detected by zirconyl haematoxylin or alcian blue. The other sugars in the oligosaccharide chains can be detected by the periodic acid-Shiff reaction. Rarely, the diagnosis of EMPD is complicated by the absence of mucin from the Paget cells. We have examined such an atypical case. The oligosaccharide side chains, including the sialic acids, are absent. In both this case and a typical case, the Paget cells contain epithelial membrane antigen mucin (MUC1) core protein and usually contain gastric surface-type mucin (MUC5AC) core protein, which can be stained by antibodies. Since neither core protein is found in normal epidermis, epithelial membrane antigen core protein may be the most reliable diagnostic marker for extramammary Paget's disease. In both the atypical case and the typical case of Paget's disease, some cells that look like keratinocytes contain mucin core proteins. These may be incipient Paget cells. We suggest that using th epithelial membrane antigen core protein as a marker for the true extent of extramammary Paget's disease could facilitate complete excision and reduce the rate of recurrence.

Coincidental Consort Clear Cell Cutaneous Carcinoma: Facial Squamous Cell Carcinoma In Situ Containing Human Papillomavirus and Cancer Cells with Clear Cytoplasm in an Octogenarian Couple

Clear cell squamous cell carcinoma in situ, also referred to as pagetoid or clear cell Bowen disease, is a rare pathologic variant of this neoplasm. It is characterized by neoplastic cells with clear or pale cytoplasm. An octogenarian husband and wife concurrently developed new facial skin lesions which demonstrated squamous cell carcinoma in situ consisting of cancer cells with clear cytoplasm. Cutaneous human papillomavirus (HPV) typing detected HPV Type 5 and HPV Type 21 in the tumors of the husband and wife, respectively. HPV is a potential etiologic factor in the oncogenesis of nonmelanoma skin cancer, and HPV DNA has been demonstrated in extragenital squamous cell carcinoma in situ. The detection of DNA from different HPV types in the tumors of our patients suggests that the concurrent occurrence of their skin cancers may have been coincidental. However, the presence of HPV DNA in their tumors introduces the possibility of a viral-associated oncogenesis for clear cell squamous cell carcinoma in situ.

Cutaneous clear cell squamous cell carcinoma in situ : clinical, histological and immunohistochemical characterization

BACKGROUND

Clear cell squamous cell carcinoma in situ (SCCIS) has not been defined in the literature with respect to its clinical, histological, and immunohistochemical features.

METHODS

Nearly 1500 consecutive cases of SCCIS were assessed for percent clear cell change. The clinical features of all SCCIS with >or=10% clear cell change, including age, sex and site distribution, were compared with classical SCCIS using chi-square analysis. PAS special staining and immunohistochemical analysis with 11 cell markers were performed to characterize the clear cell of origin.

RESULTS

Eighty SCCIS cases with a spectrum of clear cell change of >or=10% were identified. Six cases with >or=80% clear cells were defined as clear cell SCCIS. The clinical features of the cases did not vary significantly from classical SCCIS. Antibodies labeling outer root sheath (ORS) cells also labeled clear cells in the cases and included K8.12 (labeling CK13 and CK16), cellular retinoic acid binding protein II, CAM 5.2 and CK15. Antibodies that did not label ORS cells, but did label eccrine glands (CK7 and CK18) or sebocytes (EMA), also did not label the cases.

CONCLUSION

Clear cell change in SCCIS is part of a spectrum which displays ORS differentiation.

Expression of cytokeratin subtypes in intraepidermal malignancies: a guide for differentiation

BACKGROUND

Among intraepidermal malignancies of epithelial origin, Bowen's disease, bowenoid actinic keratosis (BAK), intraepidermal malignant eccrine poroma (MEP), and Paget's disease may pose diagnostic difficulties.

METHODS

Histologic features and immunohistochemical profiles of 24 cases of Bowen's disease, 21 cases of BAK, 18 cases of intraepidermal MEP, and 11 cases of Paget's disease were analyzed.

RESULTS

Using multivariate logistic regression test, multinuclear giant cells and solar degeneration were found to be the only histologic parameters of diagnostic help. On the other hand, a widespread positive reaction for CK 5/8, CK 7, CK 19, and negative reaction for CK 10, was a helpful feature in the differentiation of Paget's disease from Bowen's disease and BAK. The widespread and strong expression of CK 10 was seen in almost all cases of Bowen's disease in contrast to BAK. The widespread expression of CK 5/8 and CK 7, and negative reaction for CK 10, was in favor of Paget's disease, compared to intraepidermal MEP. On the other hand, widespread expression of CK 19 was a common finding in intraepidermal MEP, in contrast to Bowen's disease.

CONCLUSION

An immunohistochemical panel may provide significant hints on the differentiation of common intraepidermal malignancies, especially in problematic cases.

Extramammary Paget disease of the scrotum with features of Bowen disease

The scrotum is an uncommon site for the presentation of extramammary Paget disease (EMPD). We describe a case of EMPD that was discovered in a patient who had been previously diagnosed and treated for squamous cell carcinoma in situ of the scrotum 3 years earlier. Pathologic examination of the current scrotectomy specimen revealed an erythematous patch with areas of pale induration. Microscopic examination revealed areas with the characteristic histology of Paget disease adjacent to areas characteristic of Bowen disease. Immunohistochemical findings demonstrated a strong expression of carcinoembryonic antigen, cytokeratin 7, and low-molecular-weight cytokeratins (CAM 5.2) in both of these areas, giving support to the overall diagnosis of EMPD. High-molecular-weight cytokeratins (34betaE12) were uncharacteristically expressed in the cytoplasm of the Paget cells with equal or greater strength than in the surrounding keratinocytes, suggesting some degree of squamous differentiation. Very few publications have reported the coexistence of EMPD with squamous cell carcinoma in situ, occurring mostly in the vulva. To our knowledge, our case is the first report of scrotal EMPD with features of Bowen disease. Our findings support the theory that primary EMPD arises multifocally from multipotential epidermal cells.

Immunolabeling pattern of syndecan-1 expression may distinguish pagetoid Bowen's disease, extramammary Paget's disease, and pagetoid malignant melanomain situ

The differential diagnosis of pagetoid cells within the epidermis rests primarily between pagetoid Bowen's disease (PBD), extramammary Paget's disease (EPD), and pagetoid malignant melanoma (MIS) in situ. Although morphologic clues are often helpful in differentiating these lesions, the use of immunohistochemistry is often necessary to arrive at the correct diagnosis. Syndecan-1 is a cell-surface proteoglycan that mediates adhesion between cells and the extracellular matrix, and between cells themselves. Twenty-two cases of PBD, four cases of intraepidermal EPD, and 13 cases of MIS were examined for syndecan-1 immunoreactivity. Cell-membrane syndecan-1 immunoreactivity was evident in PBD, cytoplasmic syndecan-1 immunoreactivity was evident in EPD, whereas immunoreactivity for syndecan-1 was not present in MIS. The patterns of syndecan-1 immunoreactivity in these lesions may be a useful adjunct in the differentiation of PBD, EPD, and MIS.

Keratin profile of intraepidermal cells in Paget's disease, extramammary Paget's disease, and pagetoid squamous cell carcinoma in situ

BACKGROUND

Although the histopathologic differential diagnosis of pagetoid neoplasms is broad, unique histopathologic identifiers and clinical correlation can often identify the process. However, in the case of mammary Paget's disease (MPD) or extramammary Paget's disease (EPD) without an obvious underlying malignancy, distinction from pagetoid squamous cell carcinoma in situ (PSCCIS) can be challenging. Our goal was to better define the immunohistochemical staining patterns of these three entities in the hope of determining distinctive staining patterns.

METHODS

We evaluated nine cases of PSCCIS, five cases of MPD, and 10 cases of EPD with the immunohistochemical antibodies CAM 5.2 and CK 5/6. In addition, only PSCCIS was stained with CK 7, as the staining patterns of CK 7 in MPD and EPD are well known from prior studies.

RESULTS

CAM 5.2 diffusely stained all cases of MPD and EPD and failed to stain any case of PSCCIS. Furthermore, CK 7 only focally stained two of the 10 cases of PSCCIS. CK 5/6 was difficult to interpret due to the high functional background staining of the normal keratinocytes in the epidermis.

CONCLUSIONS

Based on these results, our data supports the use of CAM 5.2 and CK 7 immunoperoxidase markers in differentiating between difficult cases of PSCCIS and MPD or EPD. An antibody panel consisting of S-100, CAM 5.2, and CK 7 will aid in the accurate diagnosis of almost all pagetoid neoplasms of the breast or genital skin.

Pagetoid squamous cell carcinoma in situ (pagetoid Bowen's disease) of the external genitalia

Approximately 5% of cutaneous squamous cell carcinomas in situ (SCCIS) have a nested pattern, referred to as pagetoid SCCIS, or pagetoid Bowen's disease. This growth pattern may simulate extramammary Paget's disease (EPD) when the external genitalia are involved. We report two cases of genital pagetoid SCCIS, including the first example affecting the vulva. Using several known cases each of classic (bowenoid) SCCIS of the vulva, primary cutaneous vulvar EPD, and cutaneous melanoma in situ as controls, we performed a battery of immunohistochemical and mucin stains to study the phenotype of pagetoid SCCIS. Both cases of pagetoid SCCIS were strongly positive for cytokeratin (CK) 7, a highly sensitive and popular marker for EPD. Stains with the high molecular weight cytokeratin marker Keratin-903 (34betaE12) showed 4+ immunoreactivity, although not with the intensity seen in the juxtaposed normal keratinocytes or in the cells of classic SCCIS. Immunoreactivity scores were 2+ for CK5/6, 2+ for CK19, and 1+ to 3+ for CK 13. Unlike the Paget's cells of EPD, the nested cells of pagetoid SCCIS were devoid of mucin and were nonimmunoreactive with GCDFP-15, CEA, CAM5.2, and c-erbB2. Stains for CK20, S-100, and Melan A also were negative. Although CK7 is a sensitive marker for the Paget's cells of EPD, this study corroborates the unexpected CK7 positivity in pagetoid SCCIS, precluding its usefulness in distinguishing these two diseases. Combined with mucin stains, a limited immunohistochemical panel may be of diagnostic value in particularly difficult cases.

Vulvar Paget Disease: One Century After First Reported

OBJECTIVES.: To provide a critical assessment of the published literature on vulvar Paget disease and to allow individualized approaches to affected patients. MATERIALS AND METHODS.: A computerized search for studies published in the literature up to June 2002 was carried out using Ovid(c) and Medline databases. We excluded single case reports, letters to editors, and abstracts. RESULTS.: Historical and epidemiological aspects of vulvar Paget disease are summarized. Clinical and histopathological data support a recent proposal to classify vulvar Paget disease into two categories, primary and secondary, with significant clinical and prognostic implications. The treatment for primary vulvar Paget disease is wide and deep surgical excision. Inguinofemoral lymphadenectomy is added in the management of invasive neoplasms. In the presence of secondary Paget disease, therapy must be directed toward treatment of associated carcinoma. CONCLUSIONS.: The subclassification of vulvar Paget disease is essential for correct clinical management and treatment. Immunohistochemistry may assist in this important distinction.

Pagetoid variant of actinic keratosis with or without squamous cell carcinoma of sun-exposed skin: a lesion simulating extramammary Paget's disease

BACKGROUND

Extramammary Paget's disease usually occurs in anogenital skin. We present five cases of squamous cell carcinoma in situ of sun-exposed skin and non-squamous cell carcinoma in situ actinic keratosis that displayed atypical keratinocytes disposed in intraepithelial cell nests and immunohistochemical staining simulating extramammary Paget's disease.

METHODS AND RESULTS

Two pilot cases--one squamous cell carcinoma in situ and one non-squamous cell carcinoma in situ actinic keratosis with formation of intra-epidermal nests of atypical keratinocytes with a pagetoid spread pattern--were encountered at our institution. Fifty-four consecutive cases of squamous cell carcinoma in situ including bowenoid actinic keratosis and 34 cases of non-squamous cell carcinoma in situ actinic keratosis were reviewed to identify pagetoid spread of atypical cells. Representative sections of all cases with pagetoid spread of atypical keratinocytes were submitted for special stains for mucin, and immunostaining for cytokeratin 7 (CK7), cytokeratin 20 (CK20), cytokeratin CAM 5.2 (CAM 5.2), carcinoembryonic antigen (CEA), vimentin and S100 protein. In the group of squamous cell carcinoma in situ, 10 cases displayed pagetoid spread of atypical keratinocytes with cytoplasm ranging from clear to pale and atypical hyperchromatic nuclei. One review squamous cell carcinoma in situ was multicentric with three separate lesions. The atypical keratinocytes tended to form well to poorly defined cell groups extending from the basal cell layer to the corneal layer. No similar cases were identified in the group of non-squamous cell carcinoma in situ actinic keratosis. Two pilot cases and three of 10 review cases with a total of seven separate lesions displayed a moderate to marked immunohistochemical reactivity for CK7 similar to extramammary Paget's disease. CEA immunoreactivity was also detected in two of these cases. In addition, two of 44 squamous cell carcinomas in situ without pagetoid spread of atypical keratinocytes showed a moderate reactivity for CK7 in very occasional atypical keratinocytes. The remaining seven squamous cell carcinomas in situ with pagetoid spread of atypical keratinocytes were not immunoreactive for CEA and CK7. Immunostaining for CK20, vimentin, S100 protein was negative in all atypical cells in all study cases.

CONCLUSIONS

Actinic keratosis, particularly squamous cell carcinoma in situ of sun-exposed skin, may have histopathological and immunohistochemical features similar to extramammary Paget's disease and probably represents a variant of actinic keratosis. Awareness of the pagetoid variant of actinic keratosis arising in sun-exposed skin is helpful to avoid the over-diagnosis of extramammary Paget's disease.

Vulvar intraepithelial neoplasia: historical aspects and current status

Vulvar intraepithelial neoplasia (VIN) is the currently accepted generic designation for the spectrum of vulvar lesions with the histologic features of squamous dysplasia and squamous cell carcinoma in situ. Although several classifications of VIN have been espoused in the past 20 years, VIN can be readily classified into two principal clinicopathologic types: classic (bowenoid) VIN and simplex (differentiated) VIN. This manuscript summarizes the historical development and current status of our knowledge about VIN. Information on the clinical and pathologic aspects are detailed and illustrated, as are considerations of differential diagnosis.