Parakeratotic horns in a patient with myeloma

We describe a patient who in association with myeloma developed generalized keratotic horns. Light microscopy revealed parakeratotic plugs resembling those seen in Kyrle's disease. Electron microscopy showed distortion of keratinosomes and laminated bodies indicating a profound disturbance in keratinization. A strong C3 and weaker IgG and IgA immunofluorescence were seen in the areas of epidermal plugs and horns but no circulating epidermal antibodies were detected. All symptoms disappeared when therapy for myeloma was started favoring that they were of paraneoplastic origin.