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

Alessandra Encarnação-de Morais, Institutional Department, Department of Dermatology, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Amazonas, Brazil Marcella Caldeira-Camisasca-Souza, Institutional Department, Department of Dermatology, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Amazonas, Brazil Antônio P. Mendes-Schettini, Institutional Department, Department of Dermatology, Fundação de Dermatologia Tropical e Venereologia Alfredo da Matta, Manaus, Amazonas, Brazil Virgínia Vilasboas-Figueiras, Institutional Department, Department of Dermatology, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Amazonas, Brazil Mara L. Gomes-de Souza, Virgínia Vilasboas Figueiras Institutional Department, Department of Dermatology, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Amazonas, Brazil

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.

Keywords: Disseminated superficial actinic porokeratosis. Squamous cell carcinoma. Cutaneous neoplasms.