p185HER2 overexpression and HER2 oncogene amplification in recurrent vulvar Paget's disease

Anatomic Subtype Differences in Extramammary Paget Disease: A Meta-Analysis

Importance

Extramammary Paget disease (EMPD) is a rare, highly recurrent cutaneous malignant neoplasm of unclear origin. EMPD arises most commonly on the vulvar and penoscrotal skin. It is not presently known how anatomic subtype of EMPD affects disease presentation and management.

Objective

To compare demographic and tumor characteristics and treatment approaches for different EMPD subtypes. Recommendations for diagnosis and treatment are presented.

Data Sources

MEDLINE, Embase, Web of Science Core Collection, and Cochrane Reviews CENTRAL from December 1, 1990, to October 24, 2022.

Study Selection

Articles were excluded if they were not in English, reported fewer than 3 patients, did not specify information by anatomic subtype, or contained no case-level data. Metastatic cases on presentation were also excluded.

Data Extraction and Synthesis

Abstracts of 1295 eligible articles were independently reviewed by 5 coauthors, and 135 articles retained. Reporting was in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. The analysis was cunducted in August 2019 and updated in November 2022.

Findings

Most vulvar EMPD cases were asymptomatic, and diagnosis was relatively delayed (mean, 25.1 months). Although most vulvar EMPD cases were intraepidermal (1247/1773 [70.3%]), radical surgeries were still performed in almost one-third of cases. Despite this aggressive surgical approach, 481 of 1423 (34%) recurred, commonly confined to the skin and mucosa (177/198 [89.4%]). By contrast, 152 of 1101 penoscrotal EMPD cases (14%) recurred, but more than one-third of these recurrences were regional or associated with distant metastases (54 of 152 [35.5%]). Perianal EMPD cases recurred in one-third of cases (74/218 [33.9%]), with one-third of these recurrences being regional or associated with distant metastasis (20 of 74 [27.0%]). Perianal EMPD also had the highest rate of invasive disease (50% of cases).

Conclusions and Relevance

The diagnosis and treatment of EMPD should differ based on anatomic subtypes. Considerations for updated practice may include less morbid treatments for vulvar EMPD, which is primarily epidermal, and close surveillance for local recurrence in vulvar EMPD and metastatic recurrence in perianal EMPD. Recurrences in penoscrotal subtype were less common, and selective surveillance in this subtype may be considered. Limitations of this study include the lack of replication cohorts and the exclusion of studies that did not stratify outcomes by anatomic subtype.

Extramammary Paget Disease: a Therapeutic Challenge, for a Rare Entity

PURPOSE OF REVIEW

Extramammary Paget disease (EMPD) is a rare entity which is more frequently localized at the vulva, though it only accounts for 1-2% of vulvar neoplasms. It is a primary cutaneous adenocarcinoma whose cell of origin is still a matter of controversy: it can either arise from apocrine/eccrine glands or from stem cells. The diagnosis demands a biopsy and entails a histopathological analysis by which cells show similar characteristics as breast Paget disease.

RECENT FINDINGS

Treatment approach can entail surgery, radiotherapy, photodynamic therapy, systemic chemotherapy, and topical chemotherapy. For metastatic disease, many different chemotherapy regimens have been explored and even targeted therapy can play an important role in this disease. Since almost 30-40% of patients overexpress HER-2, trastuzumab and anti-HER-2 therapies can be employed in this setting. Due to its low incidence, there is almost no specific evidence on therapeutic interventions for this disease. Thus, there is a neat unmet need for molecular characterization of EMPD and diagnostic tools that allow clinicians to guide treatment both in the early and in the advanced disease settings. In this review, we aim to summarize available evidence about diagnosis and treatment of EMPD, both localized and metastatic, and to provide a comprehensive analysis that may help clinicians for therapeutic decisions.

Molecular Features of Preinvasive and Invasive Vulvar Neoplasms

OBJECTIVES

Neoplasms arising from the vulva are uncommon and comprise various subtypes. Given the recent advancements in the molecular aspects of oncologic pathology and how they have impacted cancer treatment, an understanding of recent innovations in the molecular features of vulvar lesions is important.

MATERIALS AND METHODS

Systematic literature search was performed on PubMed, Google Scholar, and Scopus databases for molecular and genetic characteristics of vulvar neoplasms. Peer-reviewed literature published in English is included.

RESULTS

Squamous cell carcinoma (SCC) and its precursors are the predominant neoplasm at this site. Human papillomavirus (HPV) plays a crucial role in the pathogenesis of some of these lesions. Human papillomavirus-associated SCC follows the carcinogenic pathway driven by viral proteins E6 and E7 while HPV-independent SCC shows a high incidence of mutation of TP53 and CDKN2A genes. Mutations in the genes involving the PI3K-Akt pathway play an important role in the pathogenesis of both types of SCC. Among other vulvar malignancies, melanoma, and vulvar Paget disease (VPD) pose a significant clinical challenge and have unique molecular characteristics. Compared with dermal cutaneous melanoma, vulvar melanoma shows a higher rate of mutation of cKIT and NRAS genes and a lower rate of mutations in BRAF . Less than 20% of VPD shows amplification of ERBB2 and seldom shows mutation in genes involving the PI3K-Akt pathway.

CONCLUSIONS

Several potentially targetable molecular pathways have emerged as they have been shown to be involved in the tumorigenesis of SCC, melanoma, and VPD.

The European Society of Gynaecological Oncology (ESGO), the International Society for the Study of Vulvovaginal Disease (ISSVD), the European College for the Study of Vulval Disease (ECSVD) and the European Federation for Colposcopy (EFC) consensus statements on pre-invasive vulvar lesions

The European Society of Gynaecological Oncology (ESGO), the International Society for the Study of Vulvovaginal Disease (ISSVD), the European College for the Study of Vulval Disease (ECSVD), and the European Federation for Colposcopy (EFC) developed consensus statements on pre-invasive vulvar lesions in order to improve the quality of care for patients with vulvar squamous intraepithelial neoplasia, vulvar Paget disease in situ, and melanoma in situ. For differentiated vulvar intraepithelial neoplasia (dVIN), an excisional procedure must always be adopted. For vulvar high-grade squamous intraepithelial lesion (VHSIL), both excisional procedures and ablative ones can be used. The latter can be considered for anatomy and function preservation and must be preceded by several representative biopsies to exclude malignancy. Medical treatment (imiquimod or cidofovir) can be considered for VHSIL. Recent studies favor an approach of using imiquimod in vulvar Paget's disease. Surgery must take into consideration that the extension of the disease is usually wider than what is evident in the skin. A 2 cm margin is usually considered necessary. A wide local excision with 1 cm free surgical margins is recommended for melanoma in situ. Following treatment of pre-invasive vulvar lesions, women should be seen on a regular basis for careful clinical assessment, including biopsy of any suspicious area. Follow-up should be modulated according to the risk of recurrence (type of lesion, patient age and immunological conditions, other associated lower genital tract lesions).

The European Society of Gynaecological Oncology (ESGO), the International Society for the Study of Vulvovaginal Disease (ISSVD), the European College for the Study of Vulval Disease (ECSVD) and the European Federation for Colposcopy (EFC) Consensus Statements on Pre-invasive Vulvar Lesions

ABSTRACT

The European Society of Gynaecological Oncology (ESGO), the International Society for the Study of Vulvovaginal Disease (ISSVD), the European College for the Study of Vulval Disease (ECSVD), and the European Federation for Colposcopy (EFC) developed consensus statements on pre-invasive vulvar lesions in order to improve the quality of care for patients with vulvar squamous intraepithelial neoplasia, vulvar Paget disease in situ, and melanoma in situ. For differentiated vulvar intraepithelial neoplasia (dVIN), an excisional procedure must always be adopted. For vulvar high-grade squamous intraepithelial lesion (VHSIL), both excisional procedures and ablative ones can be used. The latter can be considered for anatomy and function preservation and must be preceded by several representative biopsies to exclude malignancy. Medical treatment (imiquimod or cidofovir) can be considered for VHSIL. Recent studies favor an approach of using imiquimod in vulvar Paget's disease. Surgery must take into consideration that the extension of the disease is usually wider than what is evident in the skin. A 2 cm margin is usually considered necessary. A wide local excision with 1 cm free surgical margins is recommended for melanoma in situ. Following treatment of pre-invasive vulvar lesions, women should be seen on a regular basis for careful clinical assessment, including biopsy of any suspicious area. Follow-up should be modulated according to the risk of recurrence (type of lesion, patient age and immunological conditions, other associated lower genital tract lesions).

Hormonal Environment and HER2 Status in Extra-Mammary Paget's Disease (eMPD): A Systematic Literature Review and Meta-Analysis with Clinical Considerations

Background. Extra-mammary Paget’s disease (EMPD) is a rare neoplasm of epithelial origin, whose precise incidence is not clear. Starting from what is already known, we performed a systematic review and meta-analysis to investigate in male and female patients the immunohistochemical expression of biological markers that could serve as potential prognostic/therapeutic factors, including only human epidermal growth factor receptor 2 (HER2/neu), Estrogen Receptor (ER), Progesterone Receptor (PR), and Androgen Receptor (AR). Methods. A literature search was performed of the PubMed, Scopus, and Web of Science databases for English-language studies published from January 2000 to June 2020. Results. A total of 27 studies with 713 patients assessed the role of HER2/neu, AR, ER, and PR expression in male and female with EMPD. The overall rate of HER2/neu expression was 30%, the expression’s rate for ER and AR was 13% and 40%, respectively, and the overall rate for PR was 8%. The subgroup analysis revealed that there is a different expression of molecular markers between male and female patients. Conclusions. This study revealed that AR status and HER2/neu overexpression/amplification have been shown as two fundamental pathogenetic pathways in both female and male patients affected by EMPD.

Experiences of trastuzumab plus paclitaxel combination therapy in metastatic human epidermal growth factor receptor 2-positive extramammary Paget's disease: Four cases and a review

Tumor cells in extramammary Paget's disease sometimes overexpress human epidermal growth factor receptor 2 (HER2). Several case reports indicated successful response to HER2 inhibitor in patients with HER2-positive metastatic extramammary Paget's disease. However, these were single-case reports, and most cases were evaluated only by immunohistochemistry and treated with HER2 inhibitor monotherapy. Here, we report cases of HER2-positive metastatic extramammary Paget's disease identified by both immunohistochemistry and in situ hybridization, and the patients were treated with HER2 inhibitor (trastuzumab) and paclitaxel combination chemotherapy. Partial response was observed in one case. The case was positive on both immunohistochemistry (3+) and in situ hybridization (HER2/chromosome 17 centromere, ≥2.0). Our observations suggest that HER2 should be checked in patients with advanced and/or metastatic extramammary Paget's disease, and that therapy with HER2 blockers should be considered as an option for treatment of HER2-positive extramammary Paget's disease, especially in cases positive for both HER2 gene amplification and overexpression.

Human epidermal growth factor receptor 2 amplification as a biomarker for treatment in patients with lymph node-metastatic penoscrotal extramammary Paget's disease

The role of human epidermal growth factor receptor 2 (HER2) amplification as a biomarker for treatment in patients with lymph node (LN)-metastatic penoscrotal extramammary Paget's disease (EMPD) was investigated in the present study. A total of 11 male patients with LN-metastatic penoscrotal EMPD were retrospectively reviewed. Positron emission tomography/computed tomography (PET/CT) was conducted prior to surgery. Immunohistochemistry and fluorescence in situ hybridization were used to evaluate HER2 gene amplification in LN samples. Sanger sequencing was used to investigate HER2 mutations. A literature review of the prevalence of HER2 amplification in EMPD and the efficacy of HER2-targeted therapy was also undertaken. PET/CT is effective in detecting metastatic sites. The sensitivity and specificity of PET/CT was 90.9 and 100.0% for inguinal LNs, and 85.7 and 80.0% for pelvic LNs, respectively. The median time from LN dissection to disease progression was 15.9±1.5 months. Of the 11 patients, 3 (27.3%) indicated HER2 amplification. Patients with HER2 amplification showed shorter median times from disease discovery to LN metastasis (HER2 amplification vs HER2 non-amplification; 15.6 vs. 10.0 months; P=0.50) and from LN dissection to disease progression (HER2 amplification vs. HER2 non-amplification, 16.2 vs. 13.6 months; P=0.11). However, the aforementioned observations were not indicated to be statistically significant. No HER2 mutations were identified. Trastuzumab, a HER2-targeted monoclonal antibody, was administered to 2 of the patients with HER2 amplification. A literature review of the prevalence of HER2 amplification in EMPD and the efficacy of HER2-targeted therapy showed similar results. Altogether, 485 cases of EMPD were reported, 35 of which had metastases. The results in the present study suggest that PET/CT should be used on all metastatic EMPD patients. EMPD may be effectively treated with trastuzumab. The present study and case reports from the literature provide evidence for the benefit of testing for HER2 amplification in this rare disease and highlight the requirement for a multicenter clinical trial to assess the impact of trastuzumab therapy in treating this disease.

Human Epidermal Growth Factor Receptor 2 (HER-2/neu)-Directed Therapy for Rare Metastatic Epithelial Tumors with HER-2 Amplification

Case 1

A 67-year-old Asian female was diagnosed with locally advanced high-grade salivary duct carcinoma in June 2011. Molecular analysis revealed human epidermal growth factor receptor 2 (HER-2) amplification. She received adjuvant therapy with carboplatin/paclitaxel/ trastuzumab and maintenance of trastuzumab. Upon disease progression, trastuzumab could not be continued due to lack of financial coverage. Instead, she was treated with compassionate use of lapatinib from April 2013 and standard 5-fluorouracil. Her disease ultimately progressed and she expired later in 2013.

Case 2

A 68-year-old Asian male was diagnosed with extramammary Paget's disease of the scrotum with HER-2 amplification in May 2011. He received 6 cycles of adjuvant trastuzumab/docetaxel/carboplatin followed by maintenance trastuzumab, which was changed to compassionate use of lapatinib as his insurance did not cover further administration of trastuzumab. He showed clinical benefits from single-agent lapatinib and a combination of lapatinib/capecitabine upon progression to the single-agent lapatinib. Ultimately, he was started on ado-trastuzumab emtansine, which was approved at that time by the FDA for HER-2-positive breast cancer progressed on trastuzumab. He is having clinical and radiographic complete response based on current imaging and normalization of his tumor markers.

Conclusion

HER-2-targeted therapy should be considered for tumors with HER-2 amplification. In our case series, we would like to emphasize this approach in other rare histologies. Specifically, our patient with extramammary Paget's disease of the scrotum represents the first reported case of a non-breast, non-gastric tumor with HER-2 overexpression with complete clinical and radiographic response to HER-2-targeted therapy

Immunohistochemical study of HER2 and TUBB3 proteins in extramammary Paget disease

Metastatic extramammary Paget disease (EMPD) is a potentially fatal malignancy for which effective chemotherapy and good biomarkers are desirable for management. We investigated the status of human epidermal growth factor receptor (HER2) and neuronal β-tubulin isotype (class III β-tubulin; TUBB3), whose overexpression is a factor involved in resistance of tumor cells to taxane derivatives) in 32 patients with EMPD. HER2 status was evaluated by immunohistochemistry followed by fluorescence in situ hybridization, and TUBB3 status was evaluated by immunohistochemistry. On the basis of the US Food and Drug Administration-approved criteria, 20 (63%) of the 32 EMPD tumors were found to overexpress HER2. Positive immunoreactivity for TUBB3 was observed in 7 (22%) of the 32 patients. Although some clinicopathologic variables (nodule formation, depth of tumor cells, presence of lymph node metastasis, and serum carcinoembryonic antigen level) were significantly associated with disease outcome (P < 0.05), HER2 gain or aberrant TUBB3 expression showed no significant correlation. However, the higher incidence of HER2 gain and the relatively lower incidence of aberrant TUBB3 expression suggested that HER2-targeted immunotherapy combined with taxane derivatives is warranted for metastatic EMPD, and that HER2 and TUBB3 status might be a good biomarker for determining the most appropriate therapeutic modality.

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.

The role of immunohistochemistry in discriminating primary from secondary extramammary Paget disease

BACKGROUND

Extramammary Paget disease (EMPD) is categorized into 2 groups: primary EMPD or EMPD secondary to underlying malignancy. Primary EMPD has a better prognosis, and the ability to distinguish between the 2 subsets has clinical relevance. Recent studies have suggested that immunostains, including cytokeratin (CK) 7, CK20, and BRST-2, distinguish between the 2 groups. We analyzed a large series of EMPD with an expanded immunohistochemical panel to assess its value in distinguishing primary from secondary disease.

DESIGN

Formalin-fixed, paraffin-embedded sections of 98 EMPD specimens from 61 patients (45 primary and 16 secondary) were immunostained with CK7, CK20, HER-2/neu, BRST-2, CDX2, androgen receptor (AR), and cyclin D1. The study included 44 women and 17 men (median age: 73 years). Median follow-up time was 47 months.

RESULTS

All EMPD specimens were vibrantly positive for CK7. The frequency of positivity for all EMPD samples was CK20 (28%), BRST-2 (40%), HER-2/neu (64%), CDX2 (10%), AR (16%), and cyclin D1 (76%). For primary EMPD, the frequency of positivity was CK20 (22%), BRST-2 (48%), HER-2/neu (65%), CDX2 (2%), AR (21%), and cyclin D1 (84%). For secondary EMPD, the frequency of positivity was CK20 (50%), BRST-2 (25%), HER-2/neu (60%), CDX2 (33%), AR (0%), and cyclin D1 (53%). Notably, all 6 of 7 cases of EMPD secondary to an anorectal adenocarcinoma tested were HER-2/neu negative and 5 of those 6 cases (80%) were CDX2 positive.

CONCLUSIONS

The role of CK7, CK20, and BRST-2 in distinguishing primary and secondary EMPD is limited because CK20 and BRST-2 were positive in large subsets of both groups. An expanded immunohistochemical panel, including HER-2/neu and CDX2, may be useful in discriminating primary EMPD from EMPD secondary to anorectal adenocarcinoma but fails to distinguish primary EMPD from EMPD secondary to urothelial or prostatic malignancy. The consistent overexpression of HER-2/neu in primary EMPD suggests a role for trastuzumab therapy in patients with recurrent disease.

COX-2 and Her-2/neu are overexpressed in Paget’s disease of the vulva and the breast: results of a preliminary study

PURPOSE

Paget's disease (PD) of the breast as well as the vulva is a rare condition that accounts for about 4% of breast neoplasms and 1% of vulvar malignancies. Recurrent disease after breast and vulvar surgery might be a challenge. To evaluate relevant molecules therapeutically, tissue from mammary and vulvar PD lesions was investigated immunohistochemically.

METHODS

Histopathologic samples from 11 patients with mammary PD and eight patients with vulvar PD were stained with antibodies against estrogen and progesterone receptors, HER-2/neu and COX-2 followed by semiquantitative evaluation of the staining results.

RESULTS

All tested mammary lesions as well as seven out of eight vulvar PD were negative for estrogen and progesterone receptors. Strong membranous staining for HER-2/neu (Score 3) was seen in all cases. Six out of 8 vulvar and 10 out of 11 mammary PD showed COX-2 overexpression.

CONCLUSIONS

PD of the breast and vulva are negative for estrogens and progesterons, therefore, anti-hormonal therapy is not indicated. The high frequency of Her-2/neu and COX-2 overexpression, however, suggests that these molecules could be therapeutically relevant in patients with PD. These results require further investigation.

Extramammary Paget’s Disease in Chinese Males: A 21-year Experience

BACKGROUND

Extramammary Paget's disease (EMPD) is a rare disease in Chinese males. Our objectives were to examine the results of our experience, to correlate them with the published literature, and thus to formulate improved management guidelines.

METHODS

This was a retrospective analysis of all male patients with EMPD treated at our institution. We reviewed the patients and their case notes for data such as presenting symptoms, delay to diagnosis, incidence of concurrent malignancies, treatments given, and a variety of outcome measures, including the number of patients with recurrent or residual disease.

RESULTS

The overall recurrence rate was 35%. The risk of recurrence was reduced if intraoperative frozen section analysis was used (25%) compared to simple wide local excision (60%). Wide local excision failed to excise the disease completely in 38%. There were no associated internal malignancies and no disease-related deaths in our sample.

CONCLUSIONS

We recommend intraoperative frozen sections to reduce the risk of incomplete resection and to reduce the rate of recurrence. In our population, screening for internal malignancies can be restricted to select patients, e.g., those with perianal disease, those with invasive disease, and young patients.

Extramammary Paget's disease-a proliferation of adnexal origin?

AIM

To investigate a possible follicular origin of extramammary Paget's disease (EPD). EPD is a predominantly intraepidermal tumour with extensive involvement of adnexal structures and high recurrence rates suggesting a follicular stem cell origin. Cytokeratin (CK) 15 and CK19 are considered markers for follicular stem cells located in the hair follicle bulge region.

METHODS AND RESULTS

Formalin-fixed paraffin-embedded tissues of 12 cases of primary EPD (three anal, nine vulvar) were studied immunohistochemically with antibodies to CK15 and CK19. All cases of EPD showed polygonal Paget cells in the interfollicular epidermis, hair follicles, sebaceous and apocrine glands distributed individually, in nests and in gland-like areas. The polygonal Paget cells were intimately associated with small, flat, mitotically active, 'compressed' keratinocytes. The large Paget cells uniformly expressed CK19 in 12/12 EPD. The small 'compressed' keratinocytes showed strong cytoplasmic CK15 staining in 9/12 EPD with focal accentuation, while the polygonal Paget cells were negative.

CONCLUSIONS

These histological and immunohistochemical observations allow the following conclusions: (i) the small, flat, 'compressed' keratinocytes are an integral part of EPD; (ii) the dual cell population is reminiscent of sebaceous glands with mature sebocytes and germinative keratinocytes; (iii) since both cell types express cytokeratins typical for follicular differentiation, EPD may be a proliferation of adnexal stem cells residing in the infundibulo-sebaceous unit of hair follicles and adnexal structures.

Malignant adnexal neoplasms

Malignant cutaneous adnexal neoplasms are one of the most challenging areas of dermatopathology. Tumors of the pilosebaceous apparatus can occur as single-lineage neoplasms or may manifest as complex proliferations with multilineal differentiation patterns including not only the germinative component of the hair bulb, the inner or outer root sheath epithelium and the sebaceous gland and duct, but also the sweat duct components that relate to the apocrine secretory apparatus which empties into the follicle near the follicular bulge. Eccrine and apocrine neoplasms present a bewildering array of morphologies, which often defy precise classification. The purpose of this review is to discuss in detail the malignant neoplasms of the cutaneous adnexae and their benign and prognostically indeterminate mimics.

Polyomavirus disease in renal transplantation: review of pathological findings and diagnostic methods

Up to 10% of renal transplant recipients can develop polyomavirus nephropathy (PVN) in the allograft, leading to premature graft failure. Recent studies have shown that early diagnosis of PVN before there is irreversible damage to the kidney can result in marked improvement of outcome with resolution of the infection in a large proportion of patients. Early histopathologic diagnosis is complicated by the subtle beginning of the infection and its multifocal nature. This review presents a comprehensive set of guidelines for the effective clinical use of urine cytology and quantitation of viruria and viremia in conjunction with the renal biopsy findings. The morphological features of PVN are presented with specific emphasis on the patterns of PVN that are based on the histological progression of the disease and that correlate with clinical outcome. Also discussed in the context of their clinical significance are the main virological and epidemiological aspects of the BK, JC, and SV40 polyomavirus infections.

Androgen receptors are frequently expressed in mammary and extramammary Paget's disease

Mammary Paget's disease and extramammary Paget's disease are rare intraepithelial neoplasms. Mammary Paget's disease is almost exclusively associated with underlying invasive breast carcinoma or high-grade ductal carcinoma in situ (DCIS G3). Extramammary Paget's disease arises in areas rich in apocrine glands and is suspected to have apocrine gland origin. The aim of the study was to investigate the presence of estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR) and Her2/neu in a large number of cases. We investigated 58 cases of mammary and 23 cases of extramammary Paget's disease. Formalin-fixed and paraffin-embedded tissues were analyzed using antibodies against AR, PR, ER and Her2/neu according to standardized procedures. In mammary Paget's disease, positive immunoreactions for Her2/neu, AR and ER were observed in 56 of 58 (97%), 51 of 58 (88%), and respectively in six of 58 (10%) cases. All cases of mammary Paget's disease were negative for PR and showed a coexpression of Her2/neu and AR in 51 out of 58 cases (88%). In extramammary Paget's disease, positive immunoreactions for AR, Her2/neu and ER were observed in 18 of 23 (78%), 12 of 23 (52%), and respectively in 1 of 23 (4%) cases. All cases of extramammary Paget's disease were negative for PR and showed a coexpression of AR and Her2/neu in 12 out of 23 cases (52%). In contrast to ER and PR, AR and Her2/neu are commonly expressed in mammary and extramammary Paget's disease. The knowledge about frequent expression of AR in Paget's disease could lead to the development of a new adjuvant therapy, particularly in patients with recurrent disease.