Pagetoid dyskeratosis of the nipple epidermis: an incidental finding mimicking Paget's disease of the nipple

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.

[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.

Histopathological Grading of Oral Mucosal Chronic Graft-versus-Host Disease: Large Cohort Analysis

Graft-versus-host disease (GVHD) can manifest as acute or chronic complications in patients after hematopoietic cell transplantation (HCT). Oral chronic GVHD (cGVHD) occurs in approximately 70% of HCT recipients and includes lichenoid-like mucosal reactions, restricted mouth opening, and salivary gland dysfunction. However, the underlying histopathological presentation remains to be validated in large cohorts. We characterized the histopathological features of oral mucosal cGVHD and devised a scoring model in a large patient cohort (n = 112). Oral mucosal biopsy sections (n = 303) with and without oral cGVHD were identified from archived and current HCT recipients with additional healthy controls. Histological screening was performed on hematoxylin and eosin-stained and periodic acid-Schiff-stained sections. A points-based grading tool (0 to 19, grade 0 to IV) was established based on intraepithelial lymphocytes and band-like inflammatory infiltrate, atrophic epithelium with basal cell liquefaction degeneration, including apoptosis, as well as separation of epithelium and pseudo-rete ridges. Validation involved 62 biopsy specimens, including post-HCT (n = 47) and healthy (n = 15) specimens. Remaining biopsy specimens (n = 199) were blindly graded by 3 observers. Histological severity was correlated with clinical diagnostic and distinctive features, demonstrating a spectrum of individual patient severity, including frequent signs of subclinical GVHD in healthy mucosa. However, oral cGVHD presented with significantly higher (P < .001) scores compared with HCT controls, with moderate to high positive likelihood ratios for inflammatory infiltrate, exocytosis, and basal membrane alterations. The grade II-IV biopsy specimens demonstrated a histopathological diagnosis of active mucosal lichenoid-like cGVHD, highlighting the importance of correlating clinical presentation with the dynamic histopathological processes for improved patient stratification. In addition, this tool could be used for assessing treatments, pathological processes, and immune cellular content to provide further insight into this debilitating disease.

Pagetoid Dyskeratosis of the Male Genitalia: Case Report and Review

Pagetoid dyskeratosis is a benign incidental pathologic finding that has been reported in many distinct skin lesions on various locations of the body. A man who had pagetoid dyskeratosis within lesions of the penile shaft is described and similar cases of pagetoid dyskeratosis in lesions of the male genitalia are reviewed. The patient was a 26-year-old healthy man who developed several asymptomatic penile papules that were refractory to topical imiquimod 5% cream and cryotherapy. Snip biopsies were performed and microscopic examination revealed pagetoid dyskeratosis. PubMed was searched for the following terms: cell, clear, dyskeratosis, genitalia, pagetoid, penile, penis, prepuce, scrotum, and shaft. The papers containing these terms and their references were reviewed. Pagetoid dyskeratosis has been observed in lesions on the prepuce and scrotum; this case report now expands the distribution of this finding to the penile shaft. Clinicians and pathologists should be aware of this intriguing potential incidental finding within skin lesions of the male genitalia.

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.

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.

Proliferating pagetoid dyskeratosis: a new variant of pagetoid dyskeratosis associated with Bowen disease

Pagetoid dyskeratosis refers to a characteristic pathologic aspect of keratinocytes of the epidermis and other stratified epithelia, that have a size larger than normal, a pale cytoplasm and a pycnotic nucleus surrounded by a clear halo. This aspect has been reported, often as an incidental finding, in benign conditions. We observed a case of Bowen disease featuring pagetoid dyskeratosis remarkable because the cells concerned were in mitosis, a finding so far unreported. We call this aspect "proliferating pagetoid dyskeratosis" to differentiate it from the usual pagetoid dyskeratosis and to highlight its association with mitotic nuclei. The significance of this rare finding warrants further study.

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.

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.