Ultrasound imaging in extramammary Paget disease: Current applications and future perspectives

Extramammary Paget disease is a rare cutaneous adenocarcinoma that predominantly arises in apocrine gland-rich anatomical regions.Its nonspecific indolent clinical presentation frequently results in diagnostic delay, allowing some lesions to progress to dermal invasion, regional lymph node involvement, or distant metastasis before definitive diagnosis.Ultrasonography provides complementary information on superficial lesion morphology, tumor invasion depth, regional lymph node status, and microvascular perfusion.This narrative review synthesizes current evidence regarding the applications of ultrasonography in extramammary Paget disease, with emphasis on conventional ultrasound (US), high-frequency US, and contrast-enhanced US for morphological characterization, assessment of local invasion, evaluation of regional lymph nodes, estimation of tumor invasion depth, and monitoring of treatment response.The strengths and limitations of these modalities are critically considered, including the limited evidence base, operator dependence, and lack of standardized imaging and measurement protocols.Multimodal US may offer a more comprehensive framework by integrating structural and functional information.Nevertheless, larger prospective studies, multicenter validation, and standardized imaging criteria are required before USderived parameters can be reliably incorporated into routine clinical decisionmaking.