“Pigmented Extramammary Paget Disease”—A Potential Mimicker of Malignant Melanoma and a Pitfall in Diagnosis: A Case Report and Review of the Literature

Pigmented Epidermotropic Breast Carcinoma: A Diagnostic Pitfall Mimicking Melanoma A Case Report and Literature Review

We report the clinical and pathologic features of a patient with breast carcinoma, who developed clinically visible pigmented skin lesions during the course of the disease. The combination of clinical pigmentation, histological pagetoid epidermal spread, and considerable melanin pigment within tumour cells lead to a misdiagnosis of melanoma. This case provides a striking example of the ability of epidermotropic breast carcinoma to mimic melanoma. A literature review is also reported.

Primary melanoma of the nipple: Report of 10 cases including coexistence with Paget's disease

Primary melanoma of the nipple (PMN) is exceedingly rare, with only single cases reported to date. We identified 10 patients with PMN: 5 females, 5 males, median age 55.5 years (range 29-66) at diagnosis of melanoma in situ (4 cases) or invasive melanoma (6 cases, Breslow depth 0.2 mm to 3.5 mm). Follow-up was available for all 10 patients (median 19 months, range 1-183). Nine patients had no evidence of disease; one patient died of disease (13.5 months) after presenting with a nodal metastasis. One case was exceptional, because the patient presented with a pigmented lesion that histopathologically exhibited co-existence of melanoma in situ and Paget disease, a challenging differential diagnosis due to immunohistochemical pitfalls in distinction between melanoma in situ and the pigmented variant of mammary Paget disease. Here we report the second largest series of PMN including a case of PMN colliding with mammary Paget disease, to raise awareness of these rare malignancies.

Clinical and dermoscopic features of extramammary Paget's disease: A retrospective analysis of 49 cases

BACKGROUND

Extramammary Paget's disease (EMPD) is a rare cutaneous malignancy that can be easily confused with other diseases due to its diverse clinical manifestations, delaying the timing of treatment. Therefore, early diagnosis is extremely important. It has been reported that dermoscopy can be used to evaluate superficial skin tumors.

OBJECTIVE

To investigate the dermoscopic characteristics of EMPD diagnosed by histopathology and to develop a decision tree model that can provide clinicians with a reference to facilitate early diagnosis.

METHODS

All patients were evaluated by dermoscopic and histopathologic examinations. Dermoscopic images were assessed, and a decision tree model was constructed using SPSS (version 25.0).

RESULTS

A total of 49 patients were included in this study. We found that EMPD was most likely to be misdiagnosed when the disease duration was less than 2.5 years. Porcelain-white patches were the only key clinical feature other varying dermoscopic features could not be differentiated from those of EMPD-mimicking diseases. Polymorphic vessels were considered to be significant when the duration of the disease ranged from 0.1 year to 2.5 years. However, when the duration was >2.5 years, present (or absent) glomerular vessels were all considered EMPD.

CONCLUSIONS

Dermoscopy can be used as an auxiliary diagnostic tool for the diagnosis and management of EMPD. The decision tree can guide clinical diagnosis further validation studies are necessary due to the limited number of cases.

Mammary Paget Disease With Melanocytic Proliferation Mimicking Malignant Melanoma in situ: A Case Report

Several cases of pigmented mammary Paget’s disease (PMPD) mimicking cutaneous malignant melanoma have been reported. In these cases, the tumor cells are colonized by melanocytes, particularly with the presence of a population of melanocytes staining for HMB-45 and S100. Here, we report a case of mammary Paget disease (MPD) which was misdiagnosed as melanoma in situ due to the interpretation of the staining of melanocytic markers S-100, Melan-A, and HMB-45. The tumor cells strongly expressed CK7 and GATA3, and a dual-labeling showed negative PHH3 labeling for the melanocytes. Pathologists need to be aware of the caveat of colonization of melanocytes in Paget disease.

Pigmented epidermotropic breast cancer metastases: A rare variant with a particularly unusual feature

Pigmented epidermotropic breast cancer metastases are a rarity, often clinically misdiagnosed as melanocytic lesions. Histopathologically, they show a dermal proliferation of neoplastic metastatic cells that extend to the overlying epidermis in a pattern identical to that seen in primary Paget disease (PD). Differential diagnosis should be established with entities with a similar presentation, such as pigmented mammary PD and malignant melanoma. Immunohistochemistry may be useful for this purpose. We present a new case of pigmented epidermotropic breast cancer metastases with a particularly unusual feature: the absence of dermal infiltration by neoplastic cells, thus considered as pure epidermotropic metastatic involvement.

Extramammary Paget's Disease: Diagnosis, Pathogenesis, and Treatment with Focus on Recent Developments

Extramammary Paget’s disease (EMPD) is a rare neoplasm that usually develops in apocrine gland-bearing areas, such as the vulva, scrotum, and penis. EMPD may present with a focal, multifocal, or an ectopic lesion. Clinically, EMPD lesions often exhibit infiltrative erythema, which is sometimes similar to other skin disorders such as eczema. While primary EMPD arises as intraepithelial neoplasm of the epidermis, EMPD-like lesions may occur from epidermotropic spread of malignant cells or direct extension from an underlying internal neoplasm, known as secondary EMPD. Because treatment strategies differ for primary EMPD and secondary EMPD, accurate diagnosis based on detailed histopathological evaluation is required. In the early stages, EMPD usually shows indolent growth, and most cases are diagnosed as carcinoma in situ. However, invasive lesions may result in metastases, and deep invasion is associated with high incidence of metastases. Conventional chemotherapies have been used for EMPD treatment in patients with distant metastases, but the efficacy is not satisfactory, and the prognosis for such patients remains poor. Recent studies have provided various insights into the molecular pathogenesis of the development and advancement of EMPD, which may lead to novel treatment approaches for metastatic EMPD. This review addresses the diagnosis, pathogenesis, and treatment of EMPD with focus on recent progress in understanding this disease.

Extramammary Paget disease of the vulva

Extramammary Paget disease (EMPD) is a rare neoplasm with uncertain histogenesis, usually presenting in the anogenital area, most commonly in the vulva. The disease is characterized by slow grow and high recurrence rates. This article reviews the epidemiological, clinical, morphological, genetic and treatment features of EMPD of the vulva reported in recent years.

A challenging case of pigmented Bowen's disease and differential diagnosis of pagetoid pigmented skin lesions

Differentiation of pagetoid cutaneous neoplasms can be very challenging on hematoxylin and eosin-stained sections.

We report a singular case of pigmented pagetoid Bowen’s disease showing transitional features between extramammary Paget’s disease and in situ squamous cell carcinoma.