Fatal squamous cell carcinoma arising from transplant-associated porokeratosis.

Porokeratosis is a disorder of epidermal keratinization characterized by variably sized plaques with central depression and a well-demarcated keratotic border. Associations of porokeratosis with immunosuppression and of porokeratosis with malignancy have been observed. The authors report a case of fatal metastatic squamous cell carcinoma arising from porokeratosis in an immunosuppressed patient.