Prevalence of thyroid diseases in patients with acromegaly: experience of a Brazilian center

OBJECTIVES: Acromegaly is frequently associated with thyroid diseases. In this study, we evaluated the frequency of thyroid disorders in a series of acromegalic patients. SUBJECTS AND METHODS: We evaluated 106 acromegalic patients using thyroid ultrasonography (US) and measurements of GH, IGF-I, free T4, TSH and anti-thyroperoxidase antibody levels. IGF-I was expressed in mass units and age-related standard deviation scores (SD-scores). Fine-needle aspiration biopsy (FNAB) was performed on thyroid nodules with a diameter greater than one centimeter or with suspicious characteristics. RESULTS: Thyroid disorders were found in 75 patients. Eleven patients had diffuse goiter, 42 patients had nodular goiter, and 22 patients had unspecific morphological abnormalities. Four patients (3.8%) had thyroid carcinoma. Considering the patients with diffuse or nodular goiter, thyroid volume was greater in patients with active acromegaly, and was positively correlated with GH, IGF-I, and IGF-I SD-score. CONCLUSIONS: Our study confirmed that benign thyroid diseases are frequent in acromegalic patients. The prevalence of thyroid cancer was higher than in the overall population. We suggest that thyroid US should be routinely performed in patients with acromegaly.