Clinical data: A 23-yr-old woman was referred for aspiration cytology. She gave birth seven months ago, after which she noticed an enlarged thyroid gland.

Palpation: The right lobe was enlarged and had a not firm nodule.

Laboratory test: TSH 1.88 mIU/L.

Ultrasonography. The thyroid was echonormal. A large, dominantly echonormal occupied almost the entire right lobe. The nodule had halo and perinodular blood flow. In the upper part of the lesion, the nodule presented with regular shape while in the lower part the lesion showed nonparallel orientation. The largest depth of the nodule exceeded the largest width.

Cytology resulted in benign follicular proliferation.

A right lobectomy was performed. Histopathology disclosed benign hyperplastic nodules.

Comment. By definition, the largest diameters of a nodule should be compared when judging nonparallel orientation.