Indications for surgery and significance of unrecognized cancer in endemic multinodular goiter

The exclusion of cancer in endemic goiter is often difficult mainly because of the high number of nodules and the as-yet unclear natural history of diagnosed cancer in endemic goiter patients. In a large number of consecutive patients who were to undergo total thyroidectomy for endemic multinodular goiter, we assessed indications for surgery and thyroid cancer outcome.

All patients who were to undergo total thyroidectomy for diffuse multinodular goiter on histological examination between January 1990 and October 2008 were evaluated.

Of the 1,161 patients included in the study, 252 were cases of thyroid cancer (21.7%). Sensitivity of thyroid ultrasound (US) and fine-needle aspiration cytology (FNAC) for cancer detection was 30.3 and 64.1%, respectively. Differentiated thyroid carcinoma accounted for most of the tumors (96%), with 54.8% of them being papillary microcarcinomas, while bilateral-multicentric cancer occurred in 20.3%. In multivariate analysis, younger age (p = 0.06), sonographic findings (p = 0.03), and presence of histological thyroiditis (p = 0.09) were independently associated with the occurrence of tumors with diameter greater than 2 cm. The percentage of transient and permanent postoperative complications were approximately 25 and below 2%, respectively. After a median follow-up time of 78.5 months, overall recurrence rate was 6.7% and disease-specific mortality was 1.2%.

As US and FNAC did not consistently detect cancer in patients with diffuse multinodular goiter in our endemic area, evidence-based indications for surgery in this group of patients is needed, although radical surgery and favorable tumor histology offer favorable outcomes in commonly diagnosed thyroid cancer after total thyroidectomy for endemic multinodular goiter.