Spiny keratoderma.

We present a case of a 48-year-old man with an approximately 30-year history of spiny projections on the palms, which were histopathologically consistent with spiny keratoderma. Spiny keratoderma is a rare entity of unknown etiology that has been described with both hereditary and acquired variants. The hereditary form, which is most likely the diagnosis in our patient, manifests at a younger age and is benign. The acquired variant, which presents in older adults, has been associated with a variety of systemic diseases and malignant conditions. In patients suspected of having acquired spiny keratoderma, an evaluation for malignant conditions may be warranted.