Porokeratosis is a clonal disorder of epidermal
keratinization, which is characterized by hyperkeratotic
papules or plaques that are surrounded by a thread-like
elevated border. The histopathologic hallmark of
porokeratosis is the cornoid lamella, which is a thin column
of parakeratosis that overlies a thin or absent granular layer
and that corresponds to the raised, hyperkeratotic border.
Porokeratosis has five clinical types and malignant
degeneration has been described in all forms of
porokeratosis. We report a forty five year old farmer with a