Clinical presentation: A 49-year-old woman was referred for evaluation of a nodular goiter discovered on screening.

Palpation: no abnormality.

Functional state: euthyroidism (TSH 1.06 mIU/L).

Ultrasonography. The thyroid was echonormal and contained several cystic lesions. The lesions presented numerous comet-tail artifacts. There were two nodules with different echo patterns, a moderately hypoechogenic nodule in the right while a hypoechogenic one in the left thyroid. The former displayed intranodular vascularity while the latter was avascular.

Cytological diagnosis: benign follicular proliferation.

Combined cytological-sonographic diagnosis was benign multinodular goiter, hyperplastic nodules with great probability.

We told the patient that there is a very low risk that a surgical procedure will be required during her lifetime and offered to recheck the size of the small lesions next 3 years later. For unknown reasons the patient was operated on and a bilateral total thyroidectomy was performed.

Histopathology disclosed benign hyperplastic nodules.

Comments.

1. Comet-tail artifacts are protein rich structures and are frequently observed in cystic lesions.

2. The cytological pattern is also remarkable. The lack of colloid, the follicular growth pattern and the presence of monomorphous follicular cells argue for a well-differentiated follicular tumor. On the other hand, the presence of hyperplastic clusters is a weak while the sonographic presentation is a strong argument against a follicular tumor.