AN ADDITIONAL (NEW) ULTRASOUND SIGN OF HASHIMOTO'S LYMPHOCYTIC THYROIDITIS

Purpose: Presentation of a new ultrasound sign of Hashimoto's lymphocytic thyroiditis (HLT).

Methods and Materials: Since its introduction in clinical practice, ultrasonography (US) has proved to be a useful tool in the management of patients with thyroid disease. US enables not only to identify thyroid nodules, but also to characterize the echostructure of thyroid tissue in patients with autoimmune thyroid disease. Hashimoto's lymphocytic thyroiditis, one of the most frequent thyropathies, is a chronic inflammation of the thyroid gland. The typical sonographic features are: increase in size, fibrotic septa and micronodulation with a reduction in thyroid echogenicity. With colour Doppler marked intraparenchymal hypervascularity, chiefly arterial, is mostly detected and blood flow velocities remain within normal limits, both before and following treatment. A total of 62 children (8 (13%) boys and 54 (87%) girls, with a mean age 12,7 years, range 7–17 years) who met the diagnostic requirements for Hashimoto's lymphocytic thyroiditis (HLT) were examined. They were selected from the register of the endocrinology outpatient department.

In addition, 19 test healthy children (10 (53%) boys and 9 (47%) girls, with a mean age 8,6 years, range 3–16 years) – volunteers – without thyroid disease were examined (further referred to as Normal group). An informed written consent was obtained from all volunteers and the procedures followed were in accord with the ethical standards of our institution's committee on human experimentation.

Thyroid US evaluations were carried out by the two operators using a real-time instrument (GE LOGQ 500, microconvex transducer 3–7MHz, linear transducer 8,2–11,0MHz).

In each patient grey-scale ultrasound was performed to evaluate thyroid echogenicity and size. In all patients power Doppler and colour Doppler sonography was performed using standardized parameters. Especially, we took notice at presence and size thyroid gland adjacent lymph nodes. The size of lymph nodes were graded as small (0–5mm), medium (5–10mm) and large (>10mm).

Results: In all cases thyroid echogenicity and power Doppler suggested HLT. In all 62 children lymph nodes adjacent to the lower part of thyroid gland lobes were found. In 60 (96%) cases it was more than 1 lymph node, in 10 (16%) cases lymph nodes were localized on one side in 52 (84%) were both sided. The size of lymph node were small in 4 cases and large in 26 cases. In the Normal group we did not find lymph nodes adjacent to the lower part of thyroid gland lobes.

Conclusions: This finding suggests that lymph nodes adjacent to the lower part of thyroid gland lobes may be an additional (new) ultrasound sign of Hashimoto's lymphocytic thyroiditis.