Jung Hyun Yoon MD, Presenter: Nothing to Disclose

Jin Young Kwak MD, Abstract Co-Author: Nothing to Disclose

Eun-Kyung Kim, Abstract Co-Author: Nothing to Disclose

Hee Jung Moon MD, Abstract Co-Author: Nothing to Disclose

Min Jung Kim MD, Abstract Co-Author: Nothing to Disclose

Ji Youn Kim MD, Abstract Co-Author: Nothing to Disclose

Ji Soo Choi MD, Abstract Co-Author: Nothing to Disclose

Hyun Kyung Jung, Abstract Co-Author: Nothing to Disclose

To evaluate how to correctly manage thyroid nodules showing inadequate cytology after US-guided fine-needle aspiration biopsy (US-FNAB).

From February 2007 to March 2008, 6,178 thyroid nodules in 5,938 consecutive patients underwent US-FNAB at our institution. Of them, 1,359 (22.0%) nodules in 1,258 patients were diagnosed inadequate on cytology. A total of 736 thyroid nodules in 682 patients (M:F=645:92, mean age: 51.0 years) that underwent surgery, follow-up US-FNAB were included in this study. In the 736 thyroid nodules, 632 (85.9%) nodules were benign and 104 (14.1%) were malignant on final pathology. Clinical characteristics and US features were reviewed, and compared to the final pathologic results.

Increased age and nodule size showed significant association to malignancy (P=0.003 and P<0.001, respectively). Malignancy rates (79.8%) of nodules having suspicious US feature showed significantly higher than that (20.2%) of nodules without any suspicious US feature (P<0.001). Malignancy rates of solid nodules, mainly solid nodules, and mainly cystic nodules were 17.5%, 8.1%, and 3.3%, respectively, showing significant differences (P<0.001). Malignancy rates of nodules showing suspicious US features to those without suspicious US features were as follows; 31.6% to 5.2% (P<0.001) in solid nodules, 28.6% to 4.1% (P<0.001) in mainly solid nodules, and 25.0% to 1.8% (P=0.13) in mainly cystic nodules.

In nodules with inadequate cytology, follow-up US can be considered over repeat aspiration if there are no suspicious US features present, especially in mainly cystic nodules.

Even with inadequate cytology, patients with thyroid nodules showing no suspicious US features and mainly cystic contents, patients may be spared of difficulties of repeat aspiration for follow up.

Yoon, J, Kwak, J, Kim, E, Moon, H, Kim, M, Kim, J, Choi, J, Jung, H, What to Do with Inadequate Cytology in Thyroid Nodules? Should We Repeat Aspiration or Follow-up?.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9005205.html