title: Cribriform-morular variant of papillary thyroid carcinoma: an indication to screen for occult FAP.
abstract: Cribriform-morular variant (CMV) is a rare subtype of papillary thyroid carcinoma (PTC) that is associated with familial adenomatous polyposis (FAP). Given the high likelihood for multi-organ malignancies in FAP patients, this study explores the yield of diagnosing occult FAP among CMV-PTC patients. Institutional database was searched in order to identify patients with pathologically-confirmed CMV-PTC from 2000 to 2012. Medical records were reviewed, and clinical and pathological features were analyzed. Eleven cases of CMV were identified from 6,901 patients with PTC, for a prevalence of 0.16 %. All 11 patients were female. The median age at CMV-PTC diagnosis was 36 years (range 18-46). Two patients had pre-existing FAP at the time of PTC diagnosis. The other nine patients were referred for colonoscopy and/or genetic testing. Six patients underwent colonoscopy and one (17 %) was diagnosed with FAP based on polyposis phenotype and genetic testing. The mean age of patients at the time of CMV-PTC diagnosis was younger in the FAP group (23 years, range 18-34) than in the sporadic group (37 years, range 25-46). All three patients with FAP-associated CMV-PTC had multicentric tumors, while all five sporadic patients did not. Our study found that approximately one-sixth of patients with CMV-PTC may have occult FAP. Patients with FAP-associated CMV-PTC appear to be younger and more likely to have multicentric tumors than those with sporadic CMV-PTC. Due to the increased risk of malignancy in patients with FAP, patients with CMV-PTC should be referred for colonoscopy and/or genetic evaluation for FAP.
authors.affiliation: Colorectal Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Room C-1077, New York, NY, 10065, USA.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Levy
authors.forename: Vanessa W
authors.initials: VW
authors.lastname: Hui
authors.forename: Rupa
authors.initials: R
authors.lastname: Sood
authors.forename: Stephanie
authors.initials: S
authors.lastname: Fish
authors.forename: Arnold J
authors.initials: AJ
authors.lastname: Markowitz
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Wong
authors.forename: José G
authors.initials: JG
authors.lastname: Guillem
mesh_terms: D011125:Adenomatous Polyposis Coli / Q000150:complications*; D000293:Adolescent; D000328:Adult; D002277:Carcinoma / Q000150:complications* / Q000473:pathology*; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D008875:Middle Aged; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000150:complications* / Q000473:pathology*; D055815:Young Adult