The diagnostic categories are associated with increasing risk of malignancy running from non-diagnostic to malignant. The non-diagnostic category has a significant risk of malignancy. While the risk of malignancy for a benign diagnosis is substantial (24%), it is significantly less than that associated with an atypical or suspicious diagnosis. A suspicious diagnosis carries a risk for malignancy essentially the same as a malignant diagnosis. The categories atypical and suspicious appear to have substantially different risks for malignancy (54% vs.82%). The atypical category has twice the risk of malignancy as benign. This risk stratification may be useful for patient management.