Multicentric squamous cell carcinoma over lesions of porokeratosis palmaris et plantaris disseminata and giant porokeratosis.

Porokeratosis is a specific disorder of keratinization that has five clinical types and shows a characteristic 'cornoid lamella' on histopathology. Malignant degeneration has been described in all forms of porokeratosis. To the best of our knowledge, this is the first Indian report of multicentric squamous cell carcinoma complicating porokeratosis.