In renal graft recipients, the incidence of porokeratosis varies between 0.34 and 10.68%. 1 Disseminated superficial porokeratosis or punctuate porokeratosis are prevalent forms in organ-transplant recipients, but giant porokeratosis is very rare. Systemic immunosuppression is a well-documented trigger in genetically predisposed skin. In the patients here reported, immunosuppressive regimens included corticoids, cyclosporine, azathioprine, and tacrolimus. There is no evidence to suggest that any of the commonly used immunosuppressive drugs is more likely to induce the development of porokeratosis than another. Complete regression has been reported after discontinuation of immunosuppressive treatment. 2 One of the patients had chronic HCV infection, a condition also found associated with porokeratosis. Our two patients developed hyperkeratotic lesions on the porokeratosis plaques. The first patient had a squamous cell carcinoma that was totally excised. In some cases, the porokeratosis lesions may undergo malignant transformation to Bowen’s disease, squamous cell carcinoma, 3 basal cell carcinoma (more rarely), or melanoma. The risk of malignant degeneration increases with the size of the lesion and the patient’s age. Our patient was older than 60 years and had a large (6 × 6 cm) porokeratosis lesion. The second patient developed a verrucous lesion. Warty nodules on an annular plaque in a renal transplant recipient have been reported, which were concordant with viral warts, as in our case. 4 Although HPV testing gave negative results, the fact that HPV type 6 was detected in the first patient supports the suspicion that HPV may be involved in the appearance of superimposed hyperkeratotic lesion on porokeratosis in immunosuppressed patients.