Clinical data: a 48-year-old man requested evaluation of a lump in the right thyroid which was discovered for 3 weeks.

Palpation: an elastic nodule in the right lobe.

Functional state: euthyroidism (TSH 2.17 mIU/L).

Ultrasonography: the thyroid was echonormal. There was a mixed, peripheral-type cystic nodule in the right lobe while a smaller cystic lesion was found in the left thyroid. The former presented signs of perinodular, type 2 vascular pattern and an echonormal solid part.

On FNAC 0.5 ml bloody fuid was aspirated. There were only macropahges and a few isolated follicular cells on the smear.

Combined ultrasound-cytological diagnosis: thyroid cyst with not greater than 1% risk of malignancy.

Comments:

1. As regards the ultrasound presentation there was one feature which increased the risk of malignancy: the peripheral-type of the cyst. On the other hand, other features decreased the likelihood of carcinoma: the cyst presented blunt angle and the vascularization was not increased, the solid part was almost echonormal and did not contained microcalcification.

2. Although the cytology itself was not diagnostic, considering the ultrasound presentation we gave the above diagnosis.