[Spiny keratoderma of the palms: a case study].
Spiny keratoderma of the palms is an infrequent entity of unknown etiology. Most of the cases described are acquired, but there are also family cases. This dermatosis is characterized by the appearance of hyperkeratotic, generally asymptomatic, projections on the palms and/or soles, measuring only a few millimeters. In the histological study, parakeratotic columns of cornoid lamellae were observed on an epidermis with a thin or absent granular layer. Its association with malignant tumor pathologies of different types has been described. We present a new case of this entity, which had the peculiarity of a relationship of the parakeratotic column with the acrosyringium in some histological sections, a finding typical of a porokeratotic eccrine ostial or dermal duct nevus.