Useful immunohistochemical markers for distinguishing Paget cells from Toker cells

'Eczematous' dermatitis of the nipple: clinical and histopathological differential diagnosis of Paget disease

The nipple can be affected by many malignant and benign entities. A wide variety of diseases including Paget disease, atopic dermatitis and nipple candidiasis can cause eczema-like changes in the nipple. In cases of diagnostic uncertainty, tissue sampling may be indicated. A true eczematous lesion, such as atopic dermatitis, typically shows a spongiotic dermatitis pattern. Paget disease, on the other hand, presents with infiltration of the nipple epidermis by neoplastic cells. The presence of atypical cells scattered in the epidermis in a pagetoid pattern opens up a histopathological differential diagnosis encompassing squamous cell carcinoma in situ and malignant melanoma, among others. Immunohistochemistry is commonly used to render a diagnosis. The objective of this article is to discuss Paget disease and highlight relevant clinical and histopathological differential diagnoses.

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.

Toker Cell Hyperplasia in the Nipple-Areolar Complex of Transmasculine Individuals

We previously reported breast histopathologic features associated with testosterone therapy in transmasculine chest-contouring surgical specimens. During that study, we observed a high frequency of intraepidermal glands in the nipple-areolar complex (NAC) formed by Toker cells. This study reports Toker cell hyperplasia (TCH)-the presence of clusters of Toker cells consisting of at least 3 contiguous cells and/or glands with lumen formation-in the transmasculine population. Increased numbers of singly dispersed Toker cells were not considered TCH. Among the 444 transmasculine individuals, 82 (18.5%) had a portion of their NAC excised and available for evaluation. We also reviewed the NACs from 55 cisgender women who were aged <50 years old and had full mastectomies. The proportion of transmasculine cases with TCH (20/82; 24.4%) was 1.7-fold higher than cisgender women (8/55; 14.5%) but did not achieve significance (P = .20). However, in cases with TCH, the rate of gland formation is 2.4-fold higher in transmasculine cases, achieving borderline significance (18/82 vs 5/55; P = .06). Among transmasculine individuals, TCH was significantly more likely to be present in those with higher body mass index (P = .03). A subset of 5 transmasculine and 5 cisgender cases were stained for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), androgen receptor (AR), cytokeratin 7, and Ki67. All 10 cases were cytokeratin 7+ and Ki67-; 9 out of 10 cases were AR+. Toker cells in transmasculine cases demonstrated variable expression of ER, PR, and HER2. For cisgender cases, Toker cells were consistently ER+, PR-, and HER2-. In conclusion, there is a higher rate of TCH in the transmasculine than cisgender population, particularly among transmasculine individuals with high body mass index and taking testosterone. To our knowledge, this is the first study to demonstrate that Toker cells are AR+. Toker cell features display variable ER, PR, and HER2 immunoreactivity. The clinical significance of TCH in the transmasculine population remains to be elucidated.

HER2 Negative Mammary Paget's Disease or In Situ Melanoma? A Case Report and Review of the Literature

Mammary Paget's disease (MPD) is a rare histological condition, accounting for 1-4% of female breast cancers, which may appear either independently (1.4-13% of the cases), or in association with an in situ or invasive ductal carcinoma (approximately 90% of the cases). The purpose of this article is to highlight the histopathological challenges related to the microscopical polymorphism of this disease and the utmost importance of immunohistochemistry in the thorough process of Paget's disease differential diagnosis. Moreover, the primary objective of this review of literature was to corroborate the existing data concerning the potential peculiar immunohistochemical profile that mammary Paget's disease might express. We report the case of a 44-year-old female patient, histopathologically diagnosed with HER2-negative MPD accompanying an invasive mammary carcinoma. The histopathological and immunohistochemical approach is derived from the exigency of excluding the possibility of synchronous tumors-a mammary invasive carcinoma, accompanied by another component with MPD phenotypic mimicry. The unexpected negative HER2 reaction is conducted to a primary focus on excluding a malignant melanoma in situ. The absence of MelanA and S100 immunoexpression and lack of pigmentation and clinical aspects infirmed it. Bowen's disease was invalidated by its rare presentation in the breast cutaneous tissue and the absence of individual risk factors suggestive of an existing immunosuppressive status. In the case of similar morphoimmunohistochemical aspects, significant expression of Ki-67 signals MPD, an immunoreactivity that helped distinguish the cellular population from Toker cells. The great similarity of MPD with other benign and malignant cutaneous tumors might determine delay or misdiagnosis. Thus, the utmost importance of immunohistochemistry is reflected in its prognostic significance and geared towards extending the therapeutic arsenal.

Overall and cancer-specific survival in patients with breast Paget disease: A population-based study

Paget disease of the breast is an uncommon malignant tumor with an inferior outcome. Therefore, establishing nomograms to predict the survival outcomes of breast Paget disease patients is urgent. Clinicopathological and follow-up data of breast Paget disease patients diagnosed between 2010 and 2016 were retrieved through the Surveillance, Epidemiology, and End Result (SEER) database. The significant factors were screened out, and then those factors were utilized to build two valuable nomograms. The discriminative ability of nomograms was investigated using concordance-index (C-index), while the predictive accuracy and benefits were evaluated using calibration curves and decision curve analysis. Finally, a total of 417 breast Paget disease patients were enrolled. Tumor grade, histological type, American Joint Committee on Cancer (AJCC) stage, surgery, chemotherapy, and marital status were confirmed as independent overall survival (OS)-related factors; tumor grade, histological type, AJCC stage, and age were associated with independent cancer-specific survival (CSS)-related factors. The values of the C-index for OS nomogram acquired were 0.827 and 0.745 for training and validation cohorts, respectively. Meanwhile, the corresponding values of the C-index to CSS nomogram were 0.890 and 0.655, respectively. The calibration curves and decision curve analysis indicated that both nomograms had an excellent performance. Finally, the nomogram-based risk stratification system indicated that all breast Paget disease patients could be classified into low- and high-risk groups and showed distinct outcomes. In conclusion, two valuable nomograms incorporating various clinicopathological indicators were established for breast Paget disease patients. These prognostic nomograms provide accurate prognostic assessment for breast Paget disease patients and help clinicians select appropriate treatment strategies.

Toker cell hyperplasia in Zuska disease: A tricky association

Toker cells (TCs) are sometimes present in the nipple epidermis as oval cells with pale cytoplasm and roundish nuclei. In most cases, TCs may be easily distinguished from cancerous cells of Paget disease of the nipple (PCs). Especially in TC hyperplasia, in which mild-to-moderate atypia may be present, it may be challenging to distinguish between TCs and PCs. The combination of chronic inflammatory changes in the nipple, in the context of Zuska disease, and TC hyperplasia, may easily lead to an erroneous diagnosis of mammary Paget disease.

Combined serum carcinoembryonic antigen and cytokeratin 19 fragment levels provide a sensitive biomarker for lymph node metastasis in extramammary Paget's disease

Most cases of extramammary Paget's disease are diagnosed at an early stage. For advanced cases, few effective treatments are available and the prognosis is poor. Therefore, developing sensitive biomarkers for metastatic cases is a critical challenge. Carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA) are two potentially useful biomarkers. In the present retrospective large-scale study, we identified other potential biomarkers of lymph node metastasis. Patients with extramammary Paget's disease who visited our dermatology clinic between April 2004 and March 2019 (n = 138; mean age, 73.4 years; 85 men and 53 women) were enrolled in the study. The patients were divided into three groups according to the presence of regional lymph node metastasis and distant metastasis to evaluate the relationship between metastasis and various tumor markers: serum CEA, carbohydrate antigen (CA)19-9, CA125, CA15-3 and CYFRA. For distal metastasis, each biomarker had high sensitivity and specificity. The sensitivities and specificities for regional lymph node metastasis were as follows: CEA, 50.0% and 88.6%; CA19-9, 50% and 89.5%; CA125, 0% and 98.2%; CA15-3, 0% and 96.0%; and CYFRA, 66.7% and 95.0%, respectively. We also analyzed biomarker combinations. The sensitivity and specificity of the combination of all five biomarkers (CEA, CA19-9, CA125, CA15-3 and CYFRA) were 83.3% and 70.9%, respectively. The sensitivity of the combination of just CEA and CYFRA was also 83.3%. Screening for combinations of these biomarkers will facilitate the detection of early lymph node metastasis in patients with extramammary Paget's disease.

Pagetoid dyskeratosis in dermatopathology

Pagetoid dyskeratosis (PD) is an incidental pathologic finding that appears in several skin conditions. In an attempt to better understand PD and its incidence in dermatopathology, the authors have analyzed all skin biopsies performed over the period of 1 year in our Department of Dermatology and examined their clinical and dermatopathological variables. The criteria used for a keratinocyte to be considered a PD cell were: (1) a size larger than normal, (2) the presence of pycnotic nucleus, (3) a clear halo surrounding the nucleus, and (4) a pale eosinophilic cytoplasm. A total of 3565 biopsies were analyzed, PD cells being found in 80 cases (2.24%). Melanocytic nevi were the commonest skin lesions in which PD was observed, followed by soft fibromas, angiofibromas, and acrochordons. Most lesions were located on the head, neck, and trunk. Most cases displayed fewer than 15 PD cells per field. PD cells were normally located in the mid epidermis (frequently in clusters). The biopsies usually revealed indirect signs of rubbing, although PD cells were also found in places where rubbing was unlikely. Here, the authors report the largest series of PD analyzed to date, expanding our understanding of this striking pathological observation.

Paget's disease of the breast

Paget's disease of the breast is a rare type of cancer of the nipple–areola complex and that is often associated with an underlying in situ or invasive carcinoma. This article provides an overview and we review the main clinicopathological and therapeutic features of mammary Paget's disease.