Paget's disease versus Toker cell hyperplasia in a supernumerary nipple

A Pictorial Exploration of Mammary Paget Disease: Insights and Perspectives

Mammary Paget disease (MPD) is a rare condition primarily affecting adult women, characterized by unilateral skin changes in the nipple-areolar complex (NAC) and frequently associated with underlying breast carcinoma. Histologically, MPD is identified by large intraepidermal epithelial cells (Paget cells) with distinct characteristics. Immunohistochemical profiles aid in distinguishing MPD from other skin conditions. Clinical evaluation and imaging techniques, including magnetic resonance imaging (MRI), are recommended if MPD is suspected, although definitive diagnosis always requires histological examination. This review delves into the historical context, epidemiology, pathogenesis, clinical manifestations, and diagnosis of MPD, emphasizing the need for early detection. The classification of MPD based on pathogenesis is explored, shedding light on its varied presentations. Treatment options, including mastectomy and breast-conserving surgery, are discussed with clear guidelines for different scenarios. Adjuvant therapies are considered, particularly in cases with underlying breast cancer. Prognostic factors are outlined, underlining the importance of early intervention. Looking to the future, emerging techniques, like liquid biopsy, new immunohistochemical and molecular markers, and artificial intelligence-based image analysis, hold the potential to transform MPD diagnosis and treatment. These innovations offer hope for early detection and improved patient care, though validation through large-scale clinical trials is needed.

[Paget's disease of ectopic breast]

BACKGROUND

Paget's disease of the breast is rare, even more so when it occurs in a supernumerary breast since diagnosis is delayed due to lack of exploration and ignorance of the pathology of ectopic breast. Based on an original clinical case, we provide a clinical update concerning ectopic breast and ectopic carcinoma, including Paget's disease.

PATIENTS AND METHODS

A 44-year-old woman had complained of pain in the area of her supernumerary breast for several months. The ultrasound examination was normal but the unexplained symptoms led to performance of an excision biopsy of the lesion. This showed strictly intra-epidermal Paget's disease measuring 2mm, without any underlying carcinoma. A wider excision was performed. Follow-up at one year showed no recurrence.

DISCUSSION

An ectopic breast, present in 6 % of the population, is often ignored, despite being subject to the same diseases as anatomical breasts: it is at the origin of 0.6 % of breast cancers. Paget's disease is a rare in situ adenocarcinoma comprising fewer than 3 % of cases of breast cancer. It is extremely rare in ectopic breast. Ours is only the fourth reported case in the literature. This case is original because of the lack of objective clinical signs. Subjective symptoms such as pain, tingling, burning sensation and pruritus related to the supernumerary breast must be taken into consideration in order to enable early diagnosis of Paget's disease. Exploration by ultrasound and mammography generally appears flawed. Breast MRI may be useful but is not performed routinely. A promising future approach may consist of confocal microscopy screening of all ectopic breasts with areola or nipple patches, since this method enables the visualization of Paget cells and their organization.

Hidradenoma Papilliferum: A Clinicopathologic Study of 264 Tumors From 261 Patients, With Emphasis on Mammary-Type Alterations

Hidradenoma papilliferum (HP), also known as papillary hidradenoma, is the most common benign lesion of the female anogenital area derived from anogenital mammary-like glands (AGMLG). HP can be viewed conceptually as the cutaneous counterpart of mammary intraductal papilloma. The authors have studied 264 cases of HP, detailing various changes in the tumor and adjacent AGMLG, with emphasis on mammary-type alterations. In many HP, the authors noticed changes typical for benign breast lesions, such as sclerosing adenosis-like changes, usual, and atypical ductal hyperplasia. Almost in a third of cases, remnants of AGMLG adjacent to the lesion were evident, manifesting columnar changes reminiscent of those seen in breast lesions. This study shows that the histopathological changes in HP run a broad spectrum comparable with that in the mammary counterpart and benign breast disease.

Recurrence of breast carcinoma as Paget disease of the skin at a prior core needle biopsy site: Case report and review of the literature

INTRODUCTION

Core needle biopsy has become the preferred method of diagnosing breast carcinomas prior to definitive surgery. The possibility of displacing tumor cells into the needle track is a concern.

PRESENTATION OF CASE

A 38 year old woman was diagnosed with right breast ductal carcinoma in situ (DCIS) with microinvasion by core needle biopsy. Bilateral skin sparing mastectomies with immediate autologous reconstruction were performed. One and a half years later the patient noted erythema and a scaling crust on the skin of the right breast that progressed over several months. Punch biopsy revealed Paget disease restricted to the epidermis. Subsequent comparison to initial clinical photographs confirmed the cancer was associated with the skin puncture site of the needle biopsy. The patient underwent complete excision with skin grafting and remains free of disease three years later.

DISCUSSION

Only 13 cases of needle track recurrences have been reported. The majority presented as invasive carcinoma forming a subcutaneous mass. In the current case, detection was delayed due to not initially noting that a skin lesion was at the puncture site of the original needle biopsy. This is the only case of recurrence as tumor limited to the epidermis.

CONCLUSION

Although recurrence in a needle track occurs very infrequently, clinicians should be aware of this phenomenon and investigate any changes, particularly when occurring at a needle biopsy site. Recording the skin puncture site can aid in early detection of recurrences. Recognition of a recurrence is important for prompt treatment and optimal prognosis.

Proliferative lesions of intra-epidermal cytokeratin CAM5.2-positive cells in canine nipples

Non-keratinocyte cells with clear or vacuolated cytoplasm are frequently observed in the epidermis of canine nipples. Most of these cells express cytokeratin (CK) CAM5.2, a marker of luminal epithelial cells. The morphological and immunohistochemical characteristics of these clear cells were investigated. Nipple tissue from 36 dogs of both sexes was collected and labelled immunohistochemically for CAM5.2, CK7, CK14, CK18, CK20, α-smooth muscle actin, p63, melan-A, E-cadherin, epidermal growth factor receptor and oestrogen receptor (OR). The intra-epidermal CAM5.2(+) clear cells were present singly or as small clusters, mostly within the basal layer, in 22 dogs (61%). These cells also expressed CK7, CK18, E-cadherin and OR. Electron microscopy revealed that some of these cells had surface microvilli. Multifocal proliferative lesions consisting of these cells were observed in the nipples of four dogs. In these lesions, proliferating cells formed bilayered tubules with CAM5.2(+) inner and CK14/p63(+) outer cells. This is the first report describing intra-epidermal CAM5.2(+) clear cells, distinct from melanocytes and Merkel cells in dog nipples. These cells might arise from the luminal epithelium of the papillary duct.

Clear cells of Toker in accessory nipples

BACKGROUND

Clear cells of Toker are intraepithelial cells with clear to pale staining cytoplasm and bland cytologic features found in approximately 10% of normal nipples. Toker cells have been hypothesized as a precursor of extramammary Paget's disease (EMPD), although the distribution of Toker cells outside of the nipples has not been studied. Using immunohistochemistry, we studied 20 cases of accessory nipples for the presence of Toker cells.

METHODS

A retrospective study of 20 cases of accessory nipples was performed using routine hemotoxylin and eosin staining, as well as immunohistochemical staining for CK7, CK20, EMA, and GCDFP-15.

RESULTS

Thirteen out of 20 accessory nipples (65%) demonstrated Toker cells with CK7 staining. Toker cells in six of the 13 cases were also positive for EMA. Only one case with Toker cells showed immunoreactivity for antibodies to GCDFP-15.

CONCLUSIONS

Toker cells occur outside the normal nipple epidermis in the epidermis of accessory nipples. The distribution of Toker cells along the milk line correlates with the distribution of most cases of EMPD along the milk line, especially in the groin and axillae. Further studies are necessary to define the relationship between Toker cells and EMPD.

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.

Morphological evidence for field effect as a mechanism for tumour spread in mammary Paget's disease

AIMS

The histogenesis of mammary Paget's disease is controversial. The purpose of this study was to investigate the mechanism of tumour spread in the nipple epidermis by examining 28 cases of mammary Paget's disease associated with underlying intraductal carcinoma.

METHODS AND RESULTS

The atypical cells in the epidermis displayed a spectrum of cytological changes ranging from small-sized atypical cells located in the basal cell layer to large-sized atypical cells characteristic of Paget's cells in the upper layer of the epidermis. Serial sectioning revealed the presence of isolated, scattered and small atypical cells in the basal cell layer at the periphery of the epidermal lesion. The atypical cells, including those in the basal cell layer showed positive immunostaining for cytokeratin 7 and Her2/neu oncoprotein. Electron microscopy examination demonstrated the presence of intercellular junctions of desmosomal-like or desmosomal types between tumour cells and adjacent squamous cells. Furthermore, examination of the intraductal carcinoma of the breast tissue in cases of Paget's disease as well as control cases of intraductal carcinoma also revealed areas of skip lesions of intraductal carcinoma.

CONCLUSIONS

In view of these changes, it is unlikely that tumour expansion or tumour cell motility are sufficient explanations to account for the pattern of tumour spread in both the epidermis and the duct epithelium with skip lesions. A 'field effect' in the duct system harbouring intraductal carcinoma and the adjacent epidermis may play an important role in the tumour cell spread in the epidermis as well as in the ductal epithelium.

Mammary Paget's disease: evidence of diverse origin of the disease with a subgroup of Paget's disease developing from the superficial portion of lactiferous duct and a discontinuous pattern of tumor spread

The pattern of spread of intraductal carcinoma associated with mammary Paget's disease has not been well studied. The purpose of this study was to examine the site of origin and the pattern of tumor spread with a three-dimensional view by serial sectioning of the tissue blocks from 19 cases of Paget's disease. Intraductal carcinoma in the superficial portion of the lactiferous ducts was seen in continuity with the overlying epidermis with Paget's disease in all 19 cases. In seven cases that had adequate tissue sampling, five showed a continuous pattern of the intraductal carcinoma within the superficial as well as the deep breast tissue. In the remaining two cases, a portion of benign duct was identified between the intraductal carcinoma in the superficial lactiferous duct and the deep breast tissue. This discontinuous pattern of spread of the intraductal carcinoma was also identified in the foci of carcinoma in deep tissue. In the five cases in which the tumor involved the skin and only the superficial portions of the lactiferous duct, the leading edge of the intraductal carcinoma was seen orientated in the direction of the nipple towards the deep breast tissue. Our study of Paget's disease demonstrated that in addition to tumor spread along the lactiferous ducts from intraductal carcinoma in the deep tissue towards the nipple, there was a group of Paget's disease arising from the nipple. These lesions included: (i) lesions limited to the areolar tissue; and (ii) lesions with intraductal carcinoma involving the duct system in both superficial and deep breast tissue with and, possibly, without skip areas pattern of spread. Although certain cases of Paget's disease may appear superficial, an independent associated carcinoma in deep breast tissue has to be ruled out.