The risk of thyroid carcinoma in multinodular goiter compared to solitary thyroid nodules: A retrospective analysis of 600 patients.

BACKGROUND

It is generally believed that multinodular goiter (MNG) is associated with a lower risk of malignancy compared to solitary thyroid nodules (STN). This will be the null hypothesis in this retrospective study and we aim to prove or reject it.

METHODS

Medical files and histopathology reports of 600 patients who underwent thyroidectomy over 4-year period were reviewed. Data including patient' age, gender, presentation, ultrasonography, FNAC, surgical procedures, final histopathologic diagnosis and stage of malignant tumors were collected and analyzed. The primary end point was assessment of risk of thyroid carcinoma in patients with MNG compared to those with STN. Secondary endpoints included demographic differences and prognosis.

RESULTS

There were 459 females (76.5%). Mean age was 44.3 ± 14.5 years (range 14-85). After exclusion of 33 patients, 224 (39.5%) had STN and 343 (60.5%) had MNG. The prevalence of thyroid cancer was 41.1% (92/224) in STN compared to 29.2% (100/343) in MNG (Chi-Square = 8.593,  < 0.01). However, on multiple logistic regression analysis this correlation was found insignificant ( = 0.640). Only male gender ( = <0.000005) and preoperative impression of malignancy ( = 0.000082) were significantly associated with thyroid carcinoma.

CONCLUSION

The risk of thyroid carcinoma in STN and MNG was similar. Male gender was identified as a risk factor for thyroid cancer while age, number and size of nodules were not.