Primary extramammary Paget’s disease (EMPD) is a rare type of intraepithelial adenocarcinoma that shares histological features with Paget's disease but affects areas rich in apocrine glands outside the breast. It predominantly manifests in regions like the vulva, perianal, scrotum, and penile areas, with symptoms such as pruritus, erythema, and occasionally nodules or exudation. Unlike mammary Paget’s disease, primary EMPD affects both sexes, with a higher prevalence in Asian men and white women. The disease is rare, with an incidence of approximately 0.4-0.6 per million person-years in Europe and China. Despite its slow growth and nonspecific symptoms, primary EMPD carries significant morbidity due to high recurrence rates following surgical resection, prompting studies to identify prognostic factors like ill-defined tumor borders, exudation, and nodules.

A recent retrospective study from the First Affiliated Hospital of Chongqing Medical University aimed to analyze factors influencing postoperative recurrence of primary EMPD. The study enrolled 40 Chinese patients diagnosed between 2009 and 2019, predominantly male (77.5%), with a median age of 75.52 years. Clinical characteristics such as ill-defined tumor borders, presence of exudation, and nodules on the lesions were identified as significant risk factors for recurrence in multivariate analysis. Despite advancements in surgical techniques like wide local excision and Mohs micrographic surgery, the study highlighted challenges in early diagnosis due to misdiagnosis and delayed treatment, often mistaken for common dermatological conditions. The findings underscored the importance of vigilant clinical assessment and the need for tailored surgical approaches to improve outcomes in primary EMPD. This study contributes insights into managing primary EMPD by identifying specific clinical features associated with recurrence risk. Further research with larger cohorts and longer follow-up periods is necessary to validate these findings and refine treatment strategies for this challenging disease.

Extramammary Paget disease (EMPD) is a rare cancer primarily affecting genital and perianal areas, first described in 1889. Diagnosis can be delayed due to its subtle symptoms, but it's crucial as it often signals underlying malignancies, most commonly urothelial or anorectal. Recent epidemiological data from England suggest a fluctuating annual incidence around 0.17 per 100,000 person-years, with a noticeable decrease during the COVID-19 pandemic, highlighting its impact on diagnostic and healthcare services.