[364] Thyroid Bed Fine Needle Aspiration in Patients after Thyroidectomy – A Useful Follow-Up Tool with Proposed Diagnostic Categories

Christopher Fox, Maura O'Neil, Rashna Madan, Ossama W Tawfik, Patricia Thomas, Fang Fan. University of Kansas Medical Center, Kansas City, KS

Background: Thyroid malignancies such as papillary, medullary, and follicular carcinomas are treated by a total or near-total thyroidectomy followed by further ablation of any residual thyroid tissue via radioactive-iodine therapy. Following initial therapy, these patients are closely monitored for recurrence or metastasis. Radiologically-guided fine needle aspiration (FNA) has been used as the appropriate diagnostic modality for occult masses identified radiographically in the thyroid bed. In this study, we report our institutional experience with FNA of the thyroid bed and propose practical diagnostic categories.
Design: A retrospective chart review of all thyroid bed FNAs between April 2008 through January 2012 was performed and a cohort of 28 patients was retrieved. The cytology diagnoses were divided into five categories including: non-diagnostic, inflammatory, bland follicular cells, suspicious for malignancy and malignant. The follow up histologic and/or clinical findings were collected for each category.
Results: The 28 patients included 9 males and 19 females (ages 33-68 years). The prior thyroidectomies were due to papillary thyroid carcinoma (25 cases), follicular carcinoma (1 case), follicular adenoma (1 case), and multinodular goiter (1 case). The thyroid bed FNA diagnosis and follow-up data are shown in Table 1.

Thyroid Bed FNA Diagnostic Categories and Follow-Up Results
Thyroid bed FNA Diagnostic CategoryTotal Number of casesNo clinical evidence of recurrence/progressionSurgery performed - negativeSurgery performed - positive for recurrent diseaseNo follow-upOther
Bland Follicular Cells43010 
Suspicious for Malignancy410201 - paraganglioma

Conclusions: Radiographically-guided FNA of the thyroid bed has a high non-diagnostic rate due to the occult and hypocellular nature of this post-therapeutic site. The proposed diagnostic categories are easy to follow and provide useful information for clinical management. While clinical follow-up and/or repeat FNA may be sufficient for the first three categories, the suspicious/malignant categories have a high positive predictive value and warrant further management.
Category: Cytopathology

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 97, Tuesday Afternoon


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