Cowden syndrome.

Cowden syndrome, or the multiple hamartoma syndrome, is a familial cancer syndrome with involvement of various organ systems. Inheritance is autosomal dominant with variable expression. Progressive macrocephaly, scrotal tongue, and mild to moderate mental retardation are important signs indicating the syndrome in young children. Other mucocutaneous symptoms, for example, trichilemmomas in the nasolabial folds and palmar and plantar hyperkeratotic pits, usually become evident later in childhood. They are often accompanied by the appearance of subcutaneous lipomas and cutaneous haemangiomas.