According to the International Cowden Syndrome Consortium (2000), any of the following make the clinical diagnosis of Cowden syndrome:
* Any of these muco-cutaneous lesions:
o 6 or more facial papules, of which 3 or more must be trichilemmomata
o Cutaneous facial papules and oral mucosal papillomatosis
o Oral mucosal papillomatosis and acral keratoses
o Palmo-plantar keratoses, 6 or more
* Two major criteria BUT one must include macrocephaly or Lhermitte-Duclos disease
* One major and three minor criteria
* Four minor criteria
Pathognomonic Criteria: Major Criteria: Minor Criteria:
facial trichilemmomata breast carcinoma mental retardation
acral keratoses non-medullary thyroid cancer gastrointestinal hamartomata
papillomatous papules macrocephaly other thyroid lesions
mucosal lesions Lhermitte-Duclos disease fibrocystic breast disease
endometrial carcinoma lipomata
fibromata
genitourinary tumors or malformation
The criteria are relaxed in someone with a family history of Cowden syndrome:
* Any pathognomonic criterion OR
* Any major criterion OR
* Two minor criteria
Eng C. Will the real Cowden syndrome please stand up: revised diagnostic criteria. J Med Genet. 2000 Nov;37(11):828-30.
Pubmed record

This definition is in context to Colon Cancer. See more contextual defintions for Cowden Syndrome Diagnostic Criteria.