Endocrine Abstracts

Introduction: Surgery for benign nodular goiter (NOD) is currently limited to cancer or cosmetic deformities. Most patients are, in principle, followed up for years or decades. The long-term outcome, however, is not always clear.

Patients and methods: NOD was diagnosed as benign in 1,825 patients (1990–2015). 102 patients (5%) were treated by surgery. 95% returned to home doctors (69%) or continued to visit our clinic (518 patients, 31%). Follow-up examination (median 656 days; longest 22 years) was performed by ultrasonography (US), measurement of serum thyroglobulin (Tg), or, if necessary, fine needle aspiration cytology (FNA).

Results: Cytological diagnosis: Follow-up FNA was performed once (61%), twice (22%), thrice (8%). Most patients (69%) received the second FNA within 3 years. Morphological changes in solitary nodules: 1) VOL of solitary nodules (n=531) increased over 120% of initial VOL in 32% of patients, whereas it decreased to less than 80% in 32% of patients. 2) Cystic changes were later observed in 10% of solid nodules (n=89) and formed cysts in 74 patients (7%). Tg levels: Tg levels remained stable during 5 years (n=100). The level, however, tended to increase after 10 years of follow-up period (n=35). Clinical outcome: 4 patients (0.7%) underwent surgery within 6 years due to cosmetic reasons (2 cases) or rapid enlargement (2 cases). Papillary carcinoma in a cyst was diagnosed in one patient after 3 times of FNA. Anaplastic carcinoma developed immediately after surgery in one patient (5 years of follow-up).

Conclusions: Benign NOD was safe for life. A third of nodules shrank and a tenth formed cysts. Late surgery, although rare, may have a risk to induce an anaplastic transformation.