Clinical presentation: a 46-year-old woman was evaluated because of pain in the left side of the neck. A hypoechogenic nodule was detected on ultrasound. Aspiration cytology resulted in C-cell hyperplasia  (Dr.  Laszlo Vass, MD, PhD,  Flor Derenc Hospital, Kerepestarcsa).

Palpation: no abnormality in the thyroid.

Functional state: euthyroidism with TSH-level 2.26 mIU/L.

Ultrasonography: the right lobe was intact with a small insignificant lesion. There was a hypoechogenic lesion in the ventral part of the left lobe. The lesion had blurred borders and a type 1 vascular pattern.

Images of aspiration cytology are courtesy of Dr.  Laszlo Vass, MD, PhD. Cytological images presented in the second row arose from intraoperative imprint smear.

Blood test for calcitonin: serum-level of calcitonin was 8.78 pM/L (normal value: 0-3.36).

Histopathology: medullary cancer.

Comments:

1. The sonographic pattern is suspicious but not for a medullary but for a papillary cancer.

2. It was a very unusual situation that the pain led to the diagnosis of a medullary carcinoma.

3. Note the presence of two distinct cell populations in the images of aspiration cytology.