Table 1

International Cowden Consortium operational criteria for the diagnosis of Cowden syndrome. Ver 2000

Pathognomonic criteriaMajor criteriaMinor criteria
Mucocutaneous lesions:Breast cancerOther thyroid lesions (for example, goitre)
Trichilemmomas, facialThyroid cancer, especially follicular thyroid cancerMental retardation (IQ⩽75)
Acral keratoses Papillomatous lesionsMacrocephaly (occipital frontal circumference ⩾97th percentile)Hamartomatous intestinal polyps Fibrocystic disease of the breast
Mucosal lesionsLhermitte-Duclos disease, defined as presence of a cerebellar dysplastic gangliocytomaLipomas Fibromas
Endometrial carcinomaGenito-urinary tumours (for example, uterine fibroids, renal cell carcinoma) or genito-urinary malformation
An operational diagnosis of Cowden syndrome is made if an individual meets any one of the following criteria:
1) Pathognomic mucocutaneous lesions alone if there are:
Six or more facial papules, of which three or more must be trichilemmoma, or
Cutaneous facial papules and oral mucosal papillomatosis, or
Oral mucosal papillomatosis and acral keratoses, or
Six or more palmo plantar keratoses
2) Two major criteria but one must be either macrocephaly or Lhermitte-Duclos disease
3) One major and three minor criteria
4) Four minor criteria
In a family in which one individual meets the diagnostic criteria for Cowden syndrome, other relatives are considered to have a diagnosis of Cowden syndrome if they meet any of the following criteria:
1) A pathognomonic mucocutaneous lesion
2) Any one major criterion with or without minor criteria
3) Two minor criteria