Punctate porokeratotic keratoderma--its occurrence with internal neoplasia.

Punctate porokeratotic keratoderma (PPK) represents a diffuse involvement of palms and soles by multiple, accuminate keratotic papules and plugs, histologically identified by parakeratotic cornoid lamellae. A possible association between PPK and internal malignancy has been previously noted by Herman in 1973. A patient with a 3-month history of PPK is described in which a bronchial carcinoma was recently diagnosed. This association led us to speculate that PPK could be a sign of internal neoplasia, as already established for other forms of palmoplantar keratoderma. We suggest that the presence of an underlying malignancy must be screened for when a diagnosis of PPK is proposed.