Insights Into Mammary and Extramammary Paget's Disease: Diagnosis, Management, and Recent Advances.

Mammary Paget's disease (MPD) and extramammary Paget's disease (EMPD) are rare cutaneous disorders associated with adenocarcinoma, each presenting unique clinical challenges. MPD typically indicates an underlying breast cancer, manifesting as eczematous changes in the nipple-areolar complex. In contrast, EMPD appears as erythematous, scaly plaques in apocrine-gland-rich areas such as the vulva, perianal region, or axilla, with inconsistent links to internal malignancies. These conditions often resemble benign skin diseases, complicating timely diagnosis. Diagnosis involves clinical evaluation, imaging, and histopathological confirmation of Paget cells. Pathogenesis may stem from in situ malignant transformation or migration of cancer cells from distant sites, influenced by molecular pathways like HER2 and PI3K-AKT-mTOR. Treatment varies: MPD often requires mastectomy and systemic therapies, while EMPD is managed with surgical excision (e.g., Mohs surgery), adjusted to disease extent. The prognosis hinges on stage, molecular features, and associated tumors, particularly impacting MPD survival. Recent advances in precision medicine and immunotherapy, especially for EMPD, offer promising directions. This review highlights the distinct features, diagnostic hurdles, treatment strategies, and the essential role of a multidisciplinary approach in improving outcomes.