Repeat FNA Biopsies for Thyroid Nodules: Risk Factors for Differentiated Thyroid Cancer

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 471-496-Thyroid Neoplasia & Case Reports
Clinical
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-478
Rodis Paparodis* and Juan Carlos Jaume
University of Wisconsin - Madison, Madison, WI
Background: Ultrasound (US) guided fine needle aspiration (FNA) is the preferred method for screening thyroid nodules for thyroid cancer. Approximately 5% of the biopsied nodules are found to harbor thyroid cancer. Repeat biopsy is indicated when the original FNA is either non-diagnostic, or diagnosed as FLUS, follicular neoplasm or as a benign nodule that grows, develops suspicious clinical features and/or changes in US appearance (1). The outcomes of repeat FNA biopsies remain unclear.

Methods: We investigated the outcomes of repeated FNAs in patients with thyroid nodules, by reviewing our prospectively collected database of patients who underwent FNA at the University of Wisconsin Thyroid Multidisciplinary clinic, to identify predictors or risk factors of malignancy. We collected data for age, gender, FNA indications, cytology, ultrasound characteristics, TSH, free T4, history of hypothyroidism, TPO antibodies titer and surgical indications/surgical pathology when patients were referred for surgery. We compared categorical data by Fisher’s exact test and numerical data by student’s t test.

Results: We reviewed data from 412 repeated FNAs of 189 thyroid nodules from 153 patients: 133 females and 20 males; 15 (9.8%) had thyroid cancer on final surgical pathology. Male gender OR 5.9 (1.8-8.7; p=0.005), history of hypothyroidism (as suggested by treatment with levothyroxine) OR 3.3 (1.2-5.0; P=0.039) and presence of ultrasound identified calcifications OR 8.1 (2.4-9.7; P<0.001) at the initial FNA, were more frequent in cancer patients. Hashimoto’s cytology OR 4.5 (1.3-16.1; p=0.03) or a non-diagnostic initial FNA OR 3.5 (1.1-11.1; p=0.04) were associated with thyroid cancer. The history of radiation exposure and family history of thyroid cancer did not reach statistical significance due to small sample size (p<0.20). Age at first FNA, percentage growth of the nodule, thyroid nodule volume, baseline TSH, Free T4 or TPO titer were not predictive of cancer.

Conclusions: Repeat FNA biopsies are useful, because they identify cancer in a significant number of patients with non-diagnostic initial FNA. Male gender, history or cytological findings of Hashimoto’s and calcifications on ultrasound should further raise the index of suspicion for thyroid cancer in patients undergoing repeat FNA.

1.         Gharib H, Papini E, Paschke R, Duick DS, Valcavi R, Hegedus L, Vitti P 2010 American Association of Clinical Endocrinologists, Associazione Medici Endocrinologi, and EuropeanThyroid Association Medical Guidelines for Clinical Practice for the Diagnosis and Management of Thyroid Nodules. Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists 16 Suppl 1:1-43

Nothing to Disclose: RP, JCJ

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