Palmoplantar Papules
A 68-year-old woman presented to the dermatology clinic with a 40-year history of slowly progressing, yellowish, hyperkeratotic papules and plaques on her hands (Panel A) and feet (Panel B). She did not have any pain, itching, nail changes, or skin fragility. Similar skin lesions were present in her mother, son, and granddaughter. Biopsy of the lesions was performed, and histopathological analysis showed orthohyperkeratosis with hypergranulosis. This presentation was consistent with a diagnosis of punctate palmoplantar keratoderma. Next-generation sequencing showed a nonsense mutation (c.370C→T) in AAGAB, which encodes alpha and gamma adaptin binding protein, in the patient and her son, and a diagnosis of autosomal dominant hereditary punctate palmoplantar keratoderma type 1 was made. This type of palmoplantar keratoderma type 1 may be associated with certain types of cancer. In this patient, the results of recent chest radiography, upper endoscopy, colonoscopy, Papanicolaou testing, and mammography were unremarkable. Treatment with topical ointments with 40% urea and 20% salicylic acid were initiated, which led to a mild reduction in hyperkeratosis. Regular cancer screening was recommended.