Pagetoid variant of actinic keratosis with or without squamous cell carcinoma of sun‐exposed skin: a lesion simulating extramammary Paget's disease

Abstract

Actinic keratosis, particularly squamous cell carcinoma in situ of sun-exposed skin, may have histopathological and immunohistochemical features similar to extramammary Paget's disease and probably represents a variant of actinic keratosis. Awareness of the pagetoid variant of actinic keratosis arising in sun-exposed skin is helpful to avoid the over-diagnosis of extramammary Paget's disease.