Squamous Cell Carcinoma Developing within Lesions of Disseminated Superficial Actinic Porokeratosis

Abstract

Disseminated superficial actinic porokeratosis (DSAP) consists of multiple annular, hyperkeratotic lesions that have a bilateral distribution on sun-exposed areas, particularly the extremities. DSAPs have a wider distribution than porokeratosis of Mibelli and usually develop during the 3rd or 4th decade of life. Squamous cell carcinoma that arises in the classical type of porokeratosis of Mibelli is well-documented, but there are only a few reports of squamous cell carcinoma in DSAP. Here, we describe a 62-year-old man with DSAP who developed squamous cell carcinoma on his right forearm.

Avaliação de transformação maligna em pacientes portadores de poroceratose de Mibelli de uma mesma família

“…A associação com a doença de Bowen e carcinoma de células basais (CBC) também é descrita. [6][7][8][9][10] Esse potencial oncogênico pode ser resultante de um aumento da expressão de p53 nos queratinócitos próximos à lamela cornoide. 6,11 Nos casos relatados observamos 2 exemplos de transformação maligna em portadores de poroceratose, no primeiro caso um CEC invasivo e no segundo caso um CBC pigmentado, nas placas de poroceratose.…”

Disseminated Superficial Actinic Porokeratosis on the Face Treated with Imiquimod 5% Cream

“…Of cases reported, 7.5% have revealed a malignancy arising within the porokeratosis. Unlike other forms, DSAP does not appear to have more risk of malignant change than other types [ 8 ]. It can sometimes coexist with other forms of porokeratosis (Mibelli type, linear porokeratosis, porokeratosis palmaris et plantaris disseminata and punctate porokeratosis) [ 9 ].…”

A precancerous skin lesion that is often misdiagnosed

“…DSAP is often misdiagnosed as a rash or other skin lesion, and patients may undergo inappropriate treatment without the correct diagnosis, which is detrimental given the small risk of progression to squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and rarely melanoma. [6][7][8] Although the exact prevalence of DSAP is unknown, Australia has a higher incidence of actinic porokeratoses when compared with the rest of the world. 1 Hence, an awareness of DSAP is an essential component of any Australian GP's basic knowledge of skin disorders.…”