Tumor size predicts malignant potential in Hürthle cell neoplasms of the thyroid.
BACKGROUND
A fine needle aspiration (FNA) diagnosis of a Hürthle cell neoplasm is associated with a 20% risk of malignancy. We sought to determine if the primary tumor size correlated with the risk of malignancy in patients with a preoperative FNA diagnosis of a Hürthle cell neoplasm.


METHODS
Between January 2000 and November 2006, 57 patients underwent a thyroidectomy with a preoperative FNA diagnosis of a Hürthle cell neoplasm. Patient histories, FNA reports, operative notes, and pathology reports were retrospectively reviewed. Statistical analysis was performed.


RESULTS
The overall rate of malignancy in patients with Hürthle cell neoplasms was 21%. The average tumor size was 3.2 cm, with malignant tumors being significantly larger than benign tumors (5.0 vs. 2.7 cm, p<0.01). The risk of malignancy directly correlated with tumor size. No malignancies were seen in tumors 2 cm or smaller (0/15). The risk of malignancy was only 13% (6/46) in tumors 4 cm or smaller and increased to 55% (6/11) in tumors larger than 4 cm. All tumors larger than 6 cm were malignant (4/4).


CONCLUSIONS
Tumor size correlates directly with malignant potential in patients with Hürthle cell neoplasms of the thyroid. Among our patients, malignancy was not present in any tumors 2 cm or smaller and was present in all tumors larger than 6 cm. Because the risk of malignancy is greater than 50% in patients with a tumor larger than 4 cm, consideration should be given for an initial total thyroidectomy in these patients.
Sippel
Rebecca S
RS
Department of Surgery, University of California San Francisco and the UCSF Comprehensive Cancer Center at Mount Zion, San Francisco, CA 94143, USA. sippel@surgery.wisc.edu
Elaraj
Dina M
DM
Khanafshar
Elham
E
Zarnegar
Rasa
R
Kebebew
Electron
E
Duh
Quan-Yang
QY
Clark
Orlo H
OH
D018249:Adenoma, Oxyphilic / Q000473:pathology* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D047368:Tumor Burden