Diminishing diagnosis of follicular thyroid carcinoma.
BACKGROUND
Follicular carcinomas have been reported as 10% to 15% of thyroid malignancies. Refinements in the histologic criteria applied in the classification of follicular lesions have occurred. We aim to document the true incidence of follicular cancers in a cohort from a high-volume endocrine practice.


METHODS
Patient charts were reviewed and cancers were classified into major subtypes; papillary cancers were further classified by common variants. Proportions were compared to historic Surveillance, Epidemiology, and End Results (SEER) database proportions.


RESULTS
Only 2.7% of patients had follicular carcinoma. The proportion of patients with follicular cancer was less than the reported rates of 10% to 15%, and less than the 6.7% extrapolated from SEER.


CONCLUSIONS
The proportion of follicular cancers is less than traditionally reported. This change is due to an increased incidence of papillary cancers, and modifications of the histologic criteria used for classification of encapsulated follicular lesions. There are potential prognostic consequences, as follicular cancers have been perceived as more aggressive.
Otto
Kristen J
KJ
Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA. kotto@ent.umsmed.edu
Lam
Jacqueline S C
JS
MacMillan
Christina
C
Freeman
Jeremy L
JL
D018263:Adenocarcinoma, Follicular / Q000175:diagnosis* / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D055815:Young Adult