Endocrine Abstracts

Nodular goiter (ND) is increasingly found by image analysis. The long-term course of ND, however, is not necessarily clear and may differ in locality. The present study analyzed the changes of ND in Japanese, taking iodine-rich foods, during follow-up periods.

Patients and methods: Patients (n=4,229) were followed up to 28 years (3.4±5.8 years). Volume of nodules (VOL) by ultrasonography (US) and laboratory data, including thyroid hormones (TH), thyroglobulin (Tg), autoantibodies (Ab) and thyroid stimulating hormone (TSH), were examined. Increase rates of VOL (VIR, start from 100%) and Tg were compared in 5 periodic intervals; B-period (<2 years), C (2- yrs), D (3- yrs), E (5- yrs) and F (10- yrs).

Results: 1) VIR in 5 periods: In 6 scales (−50% to 400%-), NOD (%) of VIR<150%, clinically ‘unchanged’, decreased in A (81%) to F (43%), while NOD (%) of VIR>200%, ‘visible enlargement’ increased; A (11%) to F (46%). 2) Analysis in solitary nodules (n=1,314): a) VIR increased; B (119±82%) to F (176±140) (P<0.05). b) Serum Tg showed mild increase; B (105±82%) to F (134±131). c) US detected fluids, ‘cystic’, more in F (78%) than in B (32%). 3) Pathology: VIR of adenomatous goiter (AG) was 15% higher than that of non-AG (P<0.05). 4) Factors related to VIR: Initial VOL, Abs and length of follow-up periods were significantly related to VIR. Use of ethanol or TH-drugs also influenced VIR. 5) Late surgery (after 2 years): VIR of surgical cases (n=24, 159±133%) was higher than that of non-surgical cases (n=572, 129±96%, P=0.14).

Conclusions: NOD remained unchanged (VIR<150%) in 40% of patients over 10 years. Progression of NOD seemed to be associated with pathology, TSH and Abs. Late surgery tended to be performed in patients with higher VIR.