First examination (first row of images):

Clinical presentation: A 50-year-old woman was referred for evaluation of complaints suggesting hypothyroidism.

Palpation: Both lobes were firm.

Laboratory tests: TSH 23.7 mIU/L. Other results including serum calcium and phosphorus were in the normal range.

Ultrasonography: The thyroid was moderately hypoechogenic. There were two more hypoechogenic lesions in the dorsal part of the right lobe.

Aspiration cytology of the lesions in the dorsal part of the thyroid resulted in Hashimoto's thyroiditis.

Daily 75 microgram levothyroxine was given. We advised beside checking the TSH level, a follow-up ultrasound examination 2 years later.

Follow-up examination 3 years later (second row of images):

Clinical presentation: the patient had no complaints.

Palpation: Both lobes were firm.

Laboratory tests: TSH 2.61 mIU/L on daily 125 microgram levothyroxine.

Ultrasonography: The thyroid was unchanged. The lesions in the dorsal part of the right lobe increased in size and a small hypoechogenic area appeared in the ventral part of the left lobe.

Aspiration cytology was performed from the lesion in the dorsal part of the thyroid. We gained only scattered number of epithelial cells without any atypia.

Wash-out thyroglobulin and parathormone levels were determined, the former was 74.4 ng/mL while the latter was above 474 pg/mL.

A repeat blood test was performed. Serum thyroglobulin resulted in 11.9 ng/mL while serum parathormone level did in 180.7 pg/mL. Serum calcium was 2.94 mM/L, serum phosphorus 0.69 mM/L.

Scintigraphy disclosed parathyroid enlargement not only in the right but even in the left side.

Surgery was performed. Histopathology disclosed hyperplasia of all four parathyroids.

Comments.

1. We missed the parathyroid at first aspiration cytology.

2. The wash-out thyroglobulin of a non-thyroidal lesion covered with thyroid parenchyma is frequently elevated because the needle crosses ventral thyroid tissue.