Thyroid nodules in acromegaly : the role of elastography

Introduction: Ultrasound elastography (US-E) is a helpful tool for the diagnosis of thyroid cancer. In acromegaly, multinodular goiter is a common occurrence while the prevalence of thyroid cancer is still matter of debate. Our aims were to evaluate thyroid nodules in acromegaly and to assess the accuracy of US-E in providing information on their nature (benign vs. malignant) using cytological analysis as a reference. Materials and methods: US-E was performed in 25 patients with acromegaly (active in 10 cases, medically controlled in 8, and cured by pituitary surgery in 7), each of whom had at least one solid thyroid nodule. A total of 90 nodules were classified according to the elastography scores (ES): ES1 and ES2 for soft nodules, ES3 and ES4 for an elastic lesions. FNAC was performed in 78.6% of the ES 4 lesions and 54.1% of the ES 3 nodules. Results: Fourteen of the 90 nodules (15.5%) displayed an ES of 1, 25 (27.7%) an ES of 2, 37 (41.3%) an ES of 3, and 14 (15.5%) an ES of 4. The prevalence of hard nodules in patients with active acromegaly (68.9%) was greater than that observed in patients with cured (44.4%) or controlled (52.5%) acromegaly. The prevalence of hard nodules in the total series (56.7%) was higher than that reported in nonacromegalic goitrous subjects. All thyroid nodules subjected to FNAC were negative for malignant cells and follicular lesions. Discussion: Acromegaly (particularly active forms) is associated with a high prevalence of stiff thyroid nodules that exceeds that observed in nonacromegalic patients with goiters (33.7%). However, these nodules were never malignant at cytology, and their firmness is probably due to fibrosis. US-E therefore appears to be of limited value for the diagnosis of thyroid cancer in patients with acromegaly.