Bilateral and symmetrical palmoplantar punctate keratoses in childhood: a possible clinical clue for an early diagnosis of PTEN hamartoma-tumour syndrome

Palmoplantar punctate keratoses may be the main cutaneous sign of various diseases (porokeratosis punctata palmaris et plantaris, keratosis punctata of the palmar creases, familial punctate palmoplantar keratoderma) or represent a secondary feature [Cowden's syndrome (CS) and Darier's disease]. In CS, such keratoses usually appear during the second and third decades of life, together with other mucocutaneous features. We present the case of a 3-year-old girl with palmoplantar punctate keratoses in whom diagnosis of new-onset CS was suspected only after the development of other cutaneous lesions. Genetic analysis confirmed the diagnosis. This case highlights the necessity to consider CS in the differential diagnosis when palmoplantar punctate keratoses are found, even in paediatric patients. A prompt diagnosis is important in order to monitor the development of possible underlying associated neoplasms.