Postoperative findings and risk for malignancy in thyroid nodules with cytological diagnosis of the so-called "follicular neoplasm".
BACKGROUND
Malignant follicular lesion is not differentiated from benign lesions cytologically. The objective of this study was to assess the rate and the risk of malignancy in thyroid nodules which were cytologically diagnosed as follicular neoplasm by fine-needle aspiration (FNA) cytology.


METHODS
All the patients who had undergone surgery with cytological diagnosis of follicular neoplasm from January 1996 through December 2001 in Asan Medical Center were studied retrospectively. Patients' and nodule characteristics were analyzed for factors associated with the presence of cancer. Two hundred and fifteen patients (196 females, 19 males) were included and their mean age was 39.4 years (range: 12-76).


RESULTS
About half of the patients (102 out of 215, 47.4%) had malignancy with 29 papillary carcinomas, 57 follicular carcinomas, 15 Hürthle cell carcinomas and 1 medullary carcinoma. Previously suggested factors associated with risk for malignancy, such as male gender, large tumor size (> 4 cm) or age of patients (> 45 years), were not associated with increased risk. Diagnosis of Hürthle cell neoplasia on FNA was also not associated with increased risk. Only the extremes in age of the patients (below 20 or above 60 years) were associated with increased risk for malignancy.


CONCLUSIONS
In our findings, prevalence of carcinoma in thyroid nodule patients with cytological diagnosis of follicular neoplasm was much higher than those reported. Clinical characteristics, such as male gender, age and nodule size, are not useful predictors for the presence of malignancy. Thyroid nodules with cytological diagnosis of follicular neoplasm warrant immediate surgery.
Kim
Eun Sook
ES
Department of Internal Medicine, Ulsan University Hospital, Ulsan, Korea.
Nam-Goong
Il Seong
IS
Gong
Gyungyub
G
Hong
Suck Joon
SJ
Kim
Won Bae
WB
Shong
Young Kee
YK
D018263:Adenocarcinoma, Follicular / Q000473:pathology; D018249:Adenoma, Oxyphilic / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001707:Biopsy, Needle; D018276:Carcinoma, Medullary / Q000473:pathology; D018265:Carcinoma, Papillary, Follicular / Q000473:pathology; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000473:pathology*; D016606:Thyroid Nodule / Q000473:pathology*; D013965:Thyroidectomy; D013967:Thyroiditis, Autoimmune / Q000473:pathology