Toker cells of the breast. Morphological and immunohistochemical characterization of 40 cases

'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.

Anal intraepithelial neoplasia: a review of terminology, differential diagnoses, and patient management

Despite the knowledge of etiological association with high-risk human papilloma viruses and high-risk patient cohorts, the incidence of anal squamous cell carcinoma has continued to rise. The known precursor lesion (in particular, high-grade squamous intraepithelial lesion) makes it amenable to screening and surveillance strategies. However, the diagnosis of anal intraepithelial neoplasia suffers from interpretation challenges leading to high interobserver variability, along with numerous differential diagnoses and lingering terminology issues. Proper treatment of anal lesions requires accurate diagnosis, and while a variety of modalities are available for treatment, the rate of recurrence remains high and each modality has its own set of side effects and complications. The aim of this review article is to outline the diagnostic considerations and provide practical tips for diagnosing anal squamous intraepithelial lesions.

[Pathoanatomical algorithm for differential diagnosis of Paget's disease of the breast]

Paget's disease of the breast is a rare type of cancer that affects the skin of the nipple and usually the areola. At the same time, most patients also have one or more tumors in the immediate vicinity of the focus of mammary Paget's disease. This tumor must be distinguished from normal or atypical Toker cells, and also differentiated from diseases such as Bowen's disease of the nipple and melanocytic lesions of the nipple and areola region, including nipple melanoma and BAP1-inactivated nevus (Wiesner nevus). Currently, there is no routine pathological diagnostic algorithm for these conditions. The aim of the work is to formulate a clear clinical and morphological algorithm for diagnosing Paget's disease of the breast and Toker cells, Bowen's disease of the nipple and areola, as well as melanoma and BAP1-inactivated nevi of the above localizations. Surgical material obtained from patients with Paget's disease of the breast (18), Toker cells of the nipple (2), Bowen's disease of the nipple (6), melanoma of the nipple (1), BAP1-inactivated nevus (1) was studied. The material was examined histologically with hematoxylin and eosin staining, Alcian blue and PAS reaction, as well as immunohistochemically with the following panel of antibodies: CD138, p53, CK8, CK7, HER2/neu, EMA, HMB-45, Melan A, S-100, p63, p16 and BAP1. An easy-to-learn pathoanatomical algorithm for diagnosing Paget's cancer has been developed, which will be especially useful for pathologists who encounter pathology of the nipple and areola in their work.

Mammary Paget’s Disease: An Update

Simple Summary

Mammary Paget’s disease of the breast is an uncommon and often misdiagnosed breast malignancy. The review discusses the diagnosis, work-up, treatment, and prognosis of mammary Paget’s disease.

Abstract

Mammary Paget’s Disease is a non-invasive cutaneous malignancy of the breast involving the nipple-areolar complex that is commonly mistaken for benign breast conditions, leading to delay in diagnosis. This review article discusses Paget’s disease etiology, clinical presentation, differential diagnosis, diagnostic work-up, natural history and prognosis. This article also discusses evolving strategies for the surgical and non-surgical management of Paget’s disease.

[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.

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.

Paget disease of the vulva an analysis of 24 cases

Paget's disease can arise in the breast (mammary Paget disease) or in other locations (extramammary Paget disease) such as anogenital skin in both males and females (Paget disease of the vulva [PDV]). Underlying adenocarcinoma can be found in some cases. This study aims to report clinical aspects, surgical procedures, outcomes, and recurrences of patients with PDV.A retrospective chart review was conducted on patients with pathologically confirmed diagnosis of PDV managed at the Department of Obstetrics and Gynecology, University of Bari, and the "Giovanni Paolo II" National Cancer Institute in Bari, between 1998 and 2018.Records of 24 cases of PDV were examined. Median age of the patients at diagnosis was 69.3 (range 38-84), diagnosis of synchronous cancer was made in 2 cases and in 2 other cases of metachronous disease. Three patients had previously been diagnosed with other oncological diseases. All patients underwent surgery including wide local excision (6), simple vulvectomy (8), and extended vulvectomy (10). Lymphadenectomy was performed in 2 cases and reconstructions with advancement flaps in 7 cases. Four patients were found to have invasive disease and 1 had inguinal node involvement. Positive margins were found in 11 patients. Wound dehiscence and urethral stenosis were found in 4 and 1 case each. Eight recurrences (33.33%) were observed, regardless of positive surgical margins.PDV has a low rate of malignancy but a high rate of recurrence. It should be diagnosed early to avoid repeated surgery and to reduce symptoms and morbidity.

Mammary Paget’s Disease of the Male Breast: A Rare Case With an Unusual Immunohistochemical Profile

Mammary Paget’s disease is rare and comprises about 0.62% of all breast cancer cases, only 1.65% of which occur in male patients. This case report involves a 76-year-old man who presented to his primary care physician with an itching, scaly, unilateral lesion involving the nipple skin. He underwent wide local excision of the lesion for a diagnosis of Bowen’s disease (squamous cell carcinoma in situ). Histologic examination of the specimen revealed mammary Paget’s disease with ductal carcinoma in situ in the underlying breast tissue. A panel of immunohistochemical stains revealed the Paget cells to be positive for cytokeratin 7, MUC1, GATA3, and androgen receptor and negative for cytokeratins 5/6, p63, SOX10, and MART-1/Melan-A. Paget cells were also negative for estrogen receptor and progesterone receptor, and positive for HER2/neu. However, the underlying ductal carcinoma in situ was positive for both estrogen receptor and progesterone receptor and negative for HER2/neu. This discordance, supported by the current literature, suggests an alternative etiology for Paget’s disease in certain cases that cannot be explained by the well-established epidermotropic and transformative theories of Paget’s disease evolution.

Pre-Paget cells: Evidence of keratinocyte origin of extramammary Paget's disease

Extramammary Paget's disease (EMPD) is a carcinoma of the genital, perianal, and, rarely, axillary skin. The malignant Paget cells migrate extensively in the epidermis before invading the underlying dermis. Toker cells and keratinocytes have both been suggested as the cells of origin of EMPD. Paraffin sections of eight cases of EMPD were immunohistochemically stained for carcinoembryonic antigen, a known marker for Paget cells. The presence of carcinoembryonic antigen in some keratinocytes in all of the observed cases of EMPD suggests that EMPD originates from keratinocytes. Thus, keratinocytes containing carcinoembryonic antigen are pre-Paget cells.

Benign breast lesions that mimic malignancy

Many benign and reactive lesions of the breast show morphological overlap with malignant lesions. These benign mimics of malignancy often present diagnostic challenges to even the most experienced pathologists. This review focuses on several benign lesions of the breast that mimic malignant entities. For each of these lesions, we describe the key morphological and immunohistochemical features, potential diagnostic pitfalls, and our approach to arriving at the correct diagnosis.

Use of Immunohistochemical Stains in Epithelial Lesions of the Breast

BACKGROUND

During the last few decades, immunohistochemistry (IHC) has become an integral part of pathology. Although hematoxylin and eosin (H & E) stain remains the fundamental basis for diagnostic pathology of the breast, IHC stains provide useful and sometimes vital information. Moreover, considering the role of hormonal therapy in hormone receptor-positive breast tumors, as well as the availability of targeted chemotherapeutic agents for HER2-positive cases, IHC studies represent a major part of workups.

METHODS

A literature search was performed to explore the uses of IHC stains related to the diagnoses of breast lesions and prognostic/predictive information.

RESULTS

Selective use of IHC stains in conjunction with H & E examination helps resolve most diagnostic issues encountered by surgical pathologists during their day-to-day practice. Pathologists should be familiar with the use of each immunostain and its limitations to avoid interpretative errors.

CONCLUSIONS

IHC stains help guide the differential diagnosis of challenging epithelial lesions of the breast. They should be selectively and judiciously used and their findings must be interpreted with the differential diagnoses in mind and with an understanding of possible pitfalls.

Toker cells of the nipple are commonly associated with underlying sebaceous glands but not with lactiferous ducts

Aims

Toker cells are clear cells present in the squamous epithelium of the nipple of some women. In contrast to squamous epithelium, they are cytokeratin 7 (CK7) positive. The origin of these cells is not completely understood. It has been suggested that they may represent abortive glands or migratory ductal cells; and may be precursors of Paget's disease of the nipple. Our aim was to investigate the incidence and distribution of Toker cells and their relationship with lactiferous ducts.

Methods

We examined nipple sections from 100 consecutive mastectomies performed at Charing Cross hospital. New sections were stained for CK7 using the immunoperoxidase technique.

Results

Toker cells were identified in 11 cases. They were always clustered within the squamous epithelium superficial to sebaceous glands with no relationship with lactiferous ducts. Two cases in the study had Paget's disease and these were not associated with underlying sebaceous glands.

Conclusions

This study suggests that Toker cells are more likely to be developmentally related to sebaceous glands rather than lactiferous ducts. This raises doubts about the presence of a relationship between Toker cells and the common forms of Paget's disease, as the latter are commonly seen in association with ductal carcinoma in situ (DCIS) involving underlying lactiferous ducts. Toker cells, however, may be related to a less common form of Paget's disease which is not associated with underlying DCIS.

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.

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.

Diseases of the male nipple and areola

The male nipple-areola-complex (NAC) is a residual organ without physiologic functions in the male. It possesses similar hormone sensitivity and sexual sensitivity as the female organ. The location of the NAC on the chest wall with respect to other surface features is relevant for the male appearance. All known disseminated skin diseases may involve the nipple and areola. A number of specific localized diseases have been described in the literature, such as mammillary eczema, demodicidosis, lymphadenosis cutis benigna, nevoid hyperkeratosis, and thelalgia. Special attention is required if nipple discharge is observed. Areolar sebaceous hyperplasia and nearly all kinds of benign cutaneous tumors occur on the nipple and areola. Malignant tumors such as basal cell carcinoma, melanoma, Paget disease and other forms of breast cancer may also be found. In addition, aberrant mammary tissue may occur with a broad clinical spectrum, while absence of the nipple is an unusual observation and occurs in rare syndromes. The association of aberrant mammary tissue with urinary tract malformations has not been confirmed.

The nipple-areola complex epidermis: a prospective systematic study in adult autopsies

The prevalence of different types of clear cells and of the mite Demodex in the nipple-areola complex of adult autopsies of both sexes not suffering from breast cancer was studied in a total of 140 nipples. The epidermis of the nipple-areola complex shows squamous cells and 3 types of clear cells: Toker cells, pagetoid dyskeratosis cells, and signet ring-like cells. Toker cells were identified by standard light microscopy in 13 of 140 nipples (9.3%). Reactivity of these cells for CK7 was observed in 35 nipples (25%). They are derived from the lactiferous duct epithelium. Pagetoid dyskeratosis cells were identified in 56 of 140 nipples (40%). In 12 nipples, these cells were conspicuous (8.6%). It is suggested that the proliferation of these cells is induced by friction. Signet ring-like cells were identified in 71 nipples (50.7%). In 2 nipples, these cells were conspicuous (1.4%). They are a consequence of artefact related to formalin fixation. The prevalence of all these clear cells has no relationship with gender. Routine histopathological examination is usually enough to distinguish the characteristic features of the clear cells involving the nipple epidermis and permits differentiation of other entities with epidermal pale cells. Demodex mites were observed in 58 nipple-areola complexes (41.4%). They were more common in male nipple-areola complexes (P < 0.05). The prevalence of these mites was seen to remain steady along the years since the third decade. Demodex mites are common parasites of human nipple and are apparently of no pathologic significance.

Syringocystadenoma papilliferum on the male nipple

Syringocystadenoma papilliferum is a rare benign adnexal tumor that most frequently arises from an organoid nevus on the head and neck. Occurrence of this tumor on the male breast is extremely rare. A 74-year-old Japanese man presented with a nodule on his left nipple. Histopathological findings were typical for syringocystadenoma papilliferum. Ultrastructurally, constituent epithelial cells of the tumor were divided into three types. We focused on one cell type, undifferentiated clear cells, which have been suggested to be pluripotent cells bearing stem cell nature in syringocystadenoma papilliferum. Immunohistochemically, the tumor cells were negative for cytokeratin 15, which is known as a relatively specific marker for multipotent stem cells in the follicular bulge. We speculated that the clear cells are slightly differentiated toward apocrine rather than stem cells. We also ruled out the possibility of a relationship between the clear cells and Toker cells, which have a clear cytoplasm and are present in the areola region. Dermoscopic examination revealed amorphous milky white areas that corresponded to the pathological findings of luminal deposition of the tumor.

Lesions of the Nipple

Because of the singular anatomic structure of the nipple, some breast lesions only occur at this site. The overlying skin includes normal Toker cells near the duct orifices. These cells are occasionally so numerous as to be called Toker cell hyperplasia. Ductal carcinoma in situ (DCIS) may involve nipple skin by direct extension from the underlying ducts (Paget disease of the nipple). The numerous skin appendages (eg, sebaceous, apocrine, and eccrine glands(1)) in the nipple and areola are the likely origin of syringomatous adenomas. At the duct orifices, the normal squamous epithelium dips into the breast for a short distance and abruptly transitions to glandular luminal and myoepithelial cells. When keratin-producing cells extend deeper into the ducts, the condition of squamous metaplasia of lactiferous ducts (SMOLD) results. With age, the lactiferous sinuses are subject to weakened duct walls, inspissated secretions, and rupture, which result in the inflammatory masses or nipple discharge associated with duct ectasia. Superficial epithelial proliferations within the large lactiferous sinuses form nipple adenomas, and deeper proliferations often result in large-duct papillomas. Below the areola is a supporting smooth muscle layer that can give rise to leiomyomas, although these tumors are extraordinarily rare. The proximity of these lesions to the skin results in the majority of them presenting as palpable masses, skin changes, or nipple discharge. Biopsy specimens from these lesions may be small, superficial, or fragmented because of concern about maintaining the cosmetic appearance of the nipple and areola. Knowledge of the location of the biopsy, and the clinical presentation, is often essential in making the correct diagnosis.