Extramammary Paget's disease of the perineum: Avoiding pitfalls in diagnosis and management

Extramammary Paget's disease (EMPD) is a rare entity, especially in the perinoscrotal region, and typically presents in elderly white patients as a pruritic white or red patch in the area of distribution of apocrine glands. Typically, it affects a single site. Since its manifestations are insidious and easily misdiagnosed, the appropriate management is delayed. Management of this problem is complex and effective treatment can not only lower recurrence rates but also provide an optimal reconstructive result. The present report describes three patients with scrotal EMPD. Based on literature search, the etiopathology, diagnosis and management of these lesions is discussed. Reconstructive options, with special emphasis on scrotal lesions, are also discussed.

Pigmented extramammary Paget's disease of the axilla mimicking melanoma: case report and review of the literature

Pigmented Paget's disease is a rare variant that is often confused clinically and histologically with melanoma in situ. Herein, we describe a case of pigmented extramammary Paget's disease involving the axilla of a 79-year-old white male thought initially to represent malignant melanoma clinically and histologically. Review of the literature reveals that pigmented variant of Paget's disease, either mammary or extramammary, could be initially misdiagnosed as melanoma unless this entity is considered in the differential diagnosis, and additional confirmatory studies are performed.

Mammary and extramammary Paget's disease

Paget's disease is an intra-epidermal adenocarcinoma seen over the nipple/areola (mammary Paget's disease) or in extramammary body zones, such as the anogenital and perineal skin and the axilla. Mammary and extramammary Paget's disease share many common clinicopathological features but also show several differences, namely, with regard to pathogenesis and association with underlying malignancies. Indeed, mammary Paget's disease is as a rule associated with an underlying breast carcinoma whereas association of extramammary Paget's disease with underlying (skin or visceral) malignancies occurs much less frequently. We review here the main clinicopathological and therapeutic features of mammary and extramammary Paget's disease.

The use of cytokeratins 7 and 20 in the diagnosis of primary and secondary extramammary Paget's disease

Despite the similarity in clinical appearance, there is a significant difference in the prognosis between primary extramammary Paget's disease (EPD) and the pagetoid spread of underlying regional internal malignancy (secondary EPD, pagetoid phenomenon). Fifteen cases of primary EPD (11 carcinoma in situ and four invasive carcinoma), seven cases of secondary EPD (five colorectal adenocarcinoma and two urothelial carcinoma), and six cases of anal canal carcinoma were retrieved and analysed immunohistochemically using six kinds of monoclonal anticytokeratin antibodies. No expression of cytokeratins 1, 5, 10, 13 and 14 was observed in any cases examined in this study. All 15 cases of primary EPD had the immunophenotype cytokeratin (CK)7+/CK20-. CK20 expression was diffusely positive in six cases of secondary pagetoid spread (two urothelial carcinoma and four colorectal adenocarcinoma), and focally in one case (a colorectal adenocarcinoma). In anal canal carcinoma, three of six cases showed CK20 diffuse expression and the remaining three cases expressed CK20 focally. CK7 expression was observed in three of six cases of anal canal carcinoma and in two of five cases of secondary EPD associated with colorectal adenocarcinoma. The combination of CK7 and CK20 demonstrates these to be useful markers in distinguishing 'primary' EPD from a pagetoid spread of extracutaneous malignancies. Namely, immunophenotypes other than CK7+/CK20- in Paget cells suggest underlying regional internal malignancy.

A case of triple extramammary Paget's disease

We report a 74-year-old Japanese man with triple extramammary Paget's disease; the genital and both of the axillar regions were simultaneously involved. Literature review revealed that 27 cases of triple extramammary Paget's disease have been reported in Japan, but there are no reports of triple extramammary Paget's disease from countries other than Japan, although 2 cases of double extramammary Paget's disease are reported. In all 28 cases, including our case, the genital lesion preceded the axillary lesions. All cases except one were male and only the exceptional female case was reported to have an the invasive tumor in the dermis. We speculate that extramammary Paget's disease may appear multi-centrically.

Cutaneous metastatic disease

The relative frequencies of cutaneous metastases are similar to those of the primary cancers; breast, colon, and melanoma are the most frequent in women and lung, colon, and melanoma are the most common in men. Cutaneous metastases represent an opportunity to detect a potentially treatable cancer before other evidence of it is present, to modify therapy as appropriate to the tumor stage, or possibly to use the cutaneous lesion as a source of easily accessible tumor cells for specific therapy. Cutaneous metastatic disease as the first sign of internal cancer is most commonly seen with cancer of the lung, kidney, and ovary.