Perianal Paget’s disease: three decades experience of a single institution

Mammary and extramammary Paget's disease are uncommon intraepithelial adenocarcinomas. Both conditions have similar clinical features, which mimic inflammatory and infective diseases. Histological diagnostic confusion can arise between Paget's disease and other neoplastic conditions affecting the skin, with the most common differential diagnoses being malignant melanoma and atypical squamous disease. The glandular differentiation of both mammary Paget's disease and extramammary Paget's disease is indicated by morphological appearances, the presence of intracellular mucin in many cases, and positive immunohistochemical staining for glandular cytokeratins, epithelial membrane antigen, and carcinoembryonic antigen. This article provides an overview of mammary and extramammary Paget's disease and discusses recent evidence regarding the cell of origin. The concepts of primary and secondary Paget's disease are presented and the differential diagnosis is discussed with reference to immunohistochemical markers that might be of diagnostic value.

Extramammary Paget's disease is a rare cutaneous adenocarcinoma, usually of epidermal origin and glandular differentiation and frequently associated with an underlying adnexal carcinoma and perhaps with underlying internal malignancy. One hundred ninety-seven cases of extramammary Paget's disease (196 cases reported in the English literature from 1962 to 1982 and one case of my own) are reviewed. It remains a rare cutaneous malignancy that occurs primarily in elderly people. It is seen more frequently in women than in men and occurs predominantly in vulvar and perianal locations. Twenty-six percent of patients with this disease will ultimately die of it or an associated internal malignancy. Twenty-four percent of patients with the disease have an associated underlying cutaneous adnexal adenocarcinoma. These patients have a higher mortality rate--46%--than patients with extramammary Paget's disease without underlying cutaneous adnexal adenocarcinoma. Twelve percent of patients with extramammary Paget's disease have an associated concurrent underlying internal malignancy. The location of the underlying internal malignancy appears to be closely related to the location of the extramammary Paget's disease--i.e., a perianal location is associated with adenocarcinoma of the digestive system, a penile-scrotal-groin location with genitourinary malignancy, etc. A directed internal malignancy search may be of benefit in patients who are diagnosed as having extramammary Paget's disease.

The outcome of patients with invasive Extramammary Paget's disease (EMPD) is poorly studied. The goal of the current study was to analyze the incidence, treatment approaches and outcome of patients with invasive EMPD. We searched the SEER program database for patients diagnosed with invasive EMPD between 1973 and 2007. Demographic data, outcome and therapeutic modalities were included in the analysis. Disease specific survival (DSS) was calculated from the time of original diagnosis. 1439 patients were diagnosed with invasive EMPD. Most patients (80.4%) had localized disease, while 17.1% had locoregional spread, and 2.5% had distant disease. 1230 (86.4%) patients underwent site directed surgery, and 92 (6.4%) patients radiotherapy. 139 (9.7%) patients did not undergo any surgery or radiation therapy. The 5-year DSS was 94.9% for localized disease, 84.9% for regional disease and 52.5% for distant disease. Multivariate analysis showed a significantly shorter DSS associated with older age and advanced stage treatment modality (HR for death 1.07 and 2.5). Site directed surgery was associated with a significantly improved outcome when compared to patients who underwent no intervention (HR 0.44). Patients who received radiation, alone or in combination with site directed surgery, did not fare any better than patients who underwent surgery alone. The DSS of patients with invasive EMPD is generally favorable. A poor outcome was associated with older age, advanced stage and treatment modality. The association between a shortened DSS and the use of radiotherapy, alone or in combination with surgery, is surprising and warrants further investigation. Copyright © 2012 Elsevier Inc. All rights reserved.