Barbara White MD, Presenter: Nothing to Disclose

Barry Glenn Hansford MD, Abstract Co-Author: Nothing to Disclose

Roy Amine Raad MD, Abstract Co-Author: Nothing to Disclose

Stephen Thomas MD, Abstract Co-Author: Nothing to Disclose

Ronald Cohen, Abstract Co-Author: Nothing to Disclose

Tatjana Antic, Abstract Co-Author: Nothing to Disclose

Aytekin Oto MD, Abstract Co-Author: Consultant, General Electric Company Research grant, Koninklijke Philips Electronics NV Research grant, Bayer AG Research grant, Visualase Inc Research grant, General Electric Company

To determine the significance of non-diagnostic fine needle aspiration biopsy (FNAB) results of thyroid bed lesions in patients with thyroid cancer.

38 patients with history of thyroid cancer (29 papillary, 2 medullary, 3 follicular, 3 Hurthle, 1 non-specified) who underwent US guided FNAB of thyroid bed lesion following thyroidectomy who had diagnostic FNAB or non-diagnostic FNAB with at least one year follow-up imaging of the neck were included in the study. 22 patients had non-diagnostic FNAB results and at least one year follow-up imaging of the neck with US (n=19), CT (n=2) or MRI (n=1). Biopsy results were accepted as non-diagnostic when official pathology report was inconclusive (neither definitively benign nor malignant). Serum thyroglobulin levels (baseline and follow-up after biopsy), margin and local lymph node pathology results after thyroidectomy were also recorded.

Malignant cells were detected in 13/38 patients (34.2%) who underwent biopsy. 3/38 patients (7.8%) had a benign etiology definitively established by FNAB. FNAB results of remaining 22/38 patients (57.9%) were non-diagnostic. The patients with non-diagnostic FNAB results were then evaluated for the development of recurrences.  Of these 22 patients 9 had positive margins and 9 had positive local lymph nodes on thyroidectomy. One year follow-up imaging of the neck did not reveal local progression of the disease in any of the 22 patients. Serum thyroglobulin levels remained stable over one year.

Lack of malignant cells in the FNAB samples of thyroid bed lesions in patients with history of thyroid cancer is highly suggestive of a benign etiology regardless of margin or local lymph node positivity during surgery. These patients can be safely followed-up with imaging with at least one year interval.

In patients with history of thyroid cancer, non-diagnostic FNAB result of a thyroid bed lesion should be considered as highly suggestive of benign etiology.

White, B, Hansford, B, Raad, R, Thomas, S, Cohen, R, Antic, T, Oto, A, Fine Needle Aspiration Biopsy of the Thyroid Bed Lesions in Patients with Thyroid Cancer: What Is the Significance of Nondiagnostic Biopsy Results?.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034385.html