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. 2022 Dec 29;15(2):9634.
doi: 10.4081/dr.2023.9634. eCollection 2023 Jun 7.

A case of squamous cell carcinoma arising in a giant porokeratosis previously diagnosed as psoriasis

Lorry Aitkens  1 , Joel Byrne  1 , Charay Jennings-Dover  2 , Kathryn Anne Potter  1
Affiliations

A case of squamous cell carcinoma arising in a giant porokeratosis previously diagnosed as psoriasis

Lorry Aitkens et al. Dermatol Reports. .

Abstract

Porokeratosis (PK) is a disorder of keratinization with a clinical presentation of an atrophic center surrounded by a hyperkeratotic border. Lesions of porokeratosis carry a risk of malignant transformation with giant porokeratosis (GPK) being a high-risk variant. We report a case in which a single, large, erythematous, scaly plaque in an immunocompromised patient showed initial histopathological features consistent with psoriasis and subsequent histological features consistent with GPK. This plaque underwent malignant transformation to squamous cell carcinoma on three occasions. This case highlights that specimens taken from central portions of porokeratosis may resemble a variety of dermatoses histologically, including psoriasis, resulting in misdiagnosis as seen in our patient. When a patient presents with a diagnosis previously made that isn't responding to therapy as expected, repeat biopsy is appropriate.

Keywords: giant porokeratosis; porokeratosis; psoriasis; squamous cell carcinoma.

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Conflict of interest statement

Conflict of interest: the authors declare no potential conflict of interest.

Figures

Figure 1.
Figure 1.
An erythematous plaque with overlying scale on the left elbow exhibiting a new growth on the mediolateral portion with serosanguinous crust. A) 2018; B) 2021.
Figure 2.
Figure 2.
Year 2022. An erythematous, scaly plaque on the left elbow with a hyperkeratotic border exhibiting a new, discrete papule crust. Locations A and B were biopsied and revealed squamous cell carcinoma and giant porokeratosis, respectively.
Figure 3.
Figure 3.
The biopsy shows classic microscopic features of porokeratosis, including hyperkeratosis and cornoid lamella (angulated tiered parakeratosis overlying a localized area of epidermal dyskeratosis).
See this image and copyright information in PMC

References

    1. Ahmed A, Hivnor C. A case of genital porokeratosis and review of literature. Indian J Dermatol 2015;60:217. - PMC - PubMed
    1. Williams GM, Fillman EP. Porokeratosis. Treasure Island (FL): StatPearls; 2022.
    1. Kanitakis J, Euvrard S, Faure M, Claudy A. Porokeratosis and immunosuppression. Eur J Dermatol 1998;8:459-65. - PubMed
    1. Vence L, Thompson CB, Callen JP, Brown TS. Giant porokeratosis with malignant transformation to squamous cell carcinoma. Dermatol Surg 2018;44:580-1. - PubMed
    1. Yazkan F, Turk BG, Dereli T, Kazandi AC. Porokeratosis of Mibelli induced by topical corticosteroid. J Cutan Pathol 2006;33:516-8. - PubMed