Disseminated superficial actinic porokeratosis with progression to squamous cell carcinoma: a case report

Porokeratoses are dermatoses characterized by defective epidermal maturation, leading to the formation of abnormal cornoid lamellae.Disseminated superficial actinic porokeratosis (DSAP) is the most common variant.Malignant transformation into squamous cell carcinoma (SCC) is rare, particularly in immunosuppressed patients.A 70-year-old male with extensive photodamage, no comorbidities or immunosuppression, presented with annular papules and plaques with hyperkeratotic borders on sun-exposed areas.Biopsy of a typical lesion confirmed DSAP, while biopsy of a verrucous lesion on the right lower limb revealed SCC.Surgical excision of the malignant lesion was performed, and acitretin therapy was initiated with a good response.Clinical surveillance in chronic photo-induced dermatoses is of great importance, allowing early diagnosis of potential malignant transformation.