Pigmented Paget Disease - A Diagnostic Pitfall Mimicking Melanoma

Abstract

Pigmented mammary and extramammary Paget disease are rare entities in both males and females that mimic melanoma both clinically and histologically. Furthermore, Paget disease can be associated with increased number of benign melanocytes, thus resulting in additional diagnostic difficulty, especially when only hematoxylin and eosin-stained sections are examined and a limited immunohistochemical study is performed. Using standard hematoxylin and eosin-stained sections and routine immunohistochemical studies, we describe and characterize 7 cases of pigmented extramammary and mammary Paget disease. In all cases, malignant epithelial cells showed intracytoplasmic pigment, along with an immunohistochemical epithelial phenotype. In 2 of the cases, immunohistochemistry revealed numerous dendritic processes positive for melanocytic markers, thus resulting in an initial diagnosis of melanoma. Careful analysis confirmed that the immunolabeling corresponded to cytoplasmic labeling of melanocyte dendrites surrounding tumor cells. The correct diagnosis of pigmented Paget disease can be reached after close histologic examination and detailed evaluation of immunohistochemical studies. The latter are especially important in some extraordinary cases in which there may be an associated intraepithelial melanocytic hyperplasia.

Pigmented Mammary Paget Disease with Reticulated Features: A Rare Variant of Mammary Paget Disease

“…The main clinicopathologic differential diagnosis of PMPD is melanoma. Apart from the fact that melanoma rarely involves the nipple, there are several histologic features that differentiate PMPD from melanoma 3,4 . In the latter, large vacuolated neoplastic cells are scattered through the epidermis and they usually border directly on the dermis, with occasional invasion to the dermis.…”

Review Literature of a Case of Multiple Distant Cutaneous Metastasis From Carcinoma Breast

“…Isolated scalp skin metastases is very little involvement. (12) In general, eight specific clinical patterns associated with cutaneous breast cancer are known: cancer en cuirasse, inflammatory metastatic carcinoma (carcinoma erysipelatodes), (1,13) carcinoma teleangiectaticum, (14) alopecia neoplastica, (15,16) Paget's disease, (17,18) breast carcinoma of the inframammary crease, (19) metastatic mammary carcinoma of the eyelid with histiocytoid histology, (20) nodular metastases, (21,22) and mucinous adenocarci-noma metastatic to the skin (1) . Skin metastases from breast carcinoma can also be present in a zosteriform distribution.…”

Pigmented mammary paget’s disease mimicking melanoma in male patients: a case report and review of the literature

“…Histopathologiocally, Paget's disease is positive for CK7, EMA, CEA, and mucin, whereas negative for Melan A, HMB-45, and S-100 which are positive for melanoma [14] . Paget's cells express HER2/neu receptors and c-erb B-2 oncogene which indicate common histological and biological origin with breast carcinoma [10,15] .…”

“…Out of the cases reported only nine cases were presented as the pigmented variant of mammary Paget's disease [7,8,12,16,[19][20][21][22][23] . All reported cases of PMPD in men were associated with an underlying breast carcinoma but one (Bernadi et al).…”

“…Various underlying mechanisms and risk factors have been proposed [4][5][6][7] , however, a consensus on an existing association between PMPD and the male population or appropriate treatment methods hasn't been reached yet. To date, there haven't been any studies objectively comparing treatment protocols in the male population.…”