Thyroglobulin wash testing in the surveillance of patients with thyroid carcinoma: proposal for a reflex test

The Role of Ultrasound-Guided Fine-Needle Aspiration of Thyroid Bed Lesions and Clinical Predictors of Recurrent Papillary Thyroid Carcinoma

OBJECTIVES

Fine-needle aspiration (FNA) of thyroid bed lesions after thyroidectomy is challenging to evaluate. We determined the sensitivity, specificity, and positive and negative predicative value of thyroid bed FNA (TB-FNA) for detecting local recurrence of thyroid carcinoma.

METHODS

A retrospective search was conducted for TB-FNAs from patients with a prior thyroid resection and subsequent ipsilateral FNA from the thyroid bed. Clinical and pathologic data were retrieved from the medical record. Patients were ultimately classified as "malignant" or "benign" based on the worst pathology identified and follow-up available.

RESULTS

Forty-two cases were included, and the prior thyroidectomy pathology included 36 papillary thyroid carcinomas, two follicular carcinomas, one medullary carcinoma, and three benign cases. TB-FNA was adequate in 38 (90.5%) cases and interpreted as positive for malignancy (n = 22; 52.4%), suspicious for follicular neoplasm (n = 3; 7.1%), atypia of unknown significance (n = 2; 4.8%), and benign (n = 10; 23.8%). Twenty-seven patients had histologic follow-up, and 24 (87.5%) showed recurrent malignancy. The cytology sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 96%, 100%, 100%, 92.3%, and 97.4%, respectively, for identification of recurrent malignancy.

CONCLUSIONS

Most TB-FNA cases ultimately were diagnosed with malignancy on follow-up, although there may be sampling bias, as not all clinically benign cases had surgical follow-up.

The usefulness of fine-needle aspirates for detection of recurrent carcinoma in the thyroid bed

INTRODUCTION

Locoregional recurrence of thyroid carcinoma has a negative impact on patient prognosis. In the current study, we retrospectively reviewed cases of thyroid bed lesions in the last 3 years, correlating cytologic diagnoses with clinical findings and, whenever available, final surgical diagnosis.

MATERIALS AND METHODS

Cytologic results and needle wash thyroglobulin results from patients with fine-needle aspiration (FNA) of thyroid bed lesions were retrospectively collected from our electronic files. Additional retrieved data included sex, age at diagnosis, previous thyroidectomy diagnosis, time lapse since surgery, and corresponding surgical diagnosis (whenever available).

RESULTS

A total of 91 cases from 72 patients (54 F, 18 M) were retrieved from the electronic files, with a median age of 49 years. Average interval between surgery and thyroid bed FNA was 5 years. Thyroglobulin levels were available for 60 (65.2%) cases. The average level was 276.2 ug/mL, with a range of <0.1 to 4720 ug/mL. Information on final surgical diagnosis was available for 31 samples. Complete agreement between final cytologic and histologic diagnoses was achieved in 28 of 31 (90.3%) of the cases, with 1 false negative and 2 false positives. Cytology sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 95.2%, 71.4%, 90.9%, 83.3%, and 89.1%, respectively.

CONCLUSIONS

Ultrasound-guided FNA is an accurate and minimally invasive diagnostic method for suspicious thyroid bed lesions, with high sensitivity and positive predictive value.