The occurrence of thyroid focal lesions and a need for fine needle aspiration biopsy in patients with acromegaly due to an increased risk of thyroid cancer.

OBJECTIVE: The high prevalence of goiter in acromegalic patients is well known. Several studies revealed increased frequency of thyroid carcinoma in these patients. The aim of the study was to evaluate the incidence of thyroid lesions, including thyroid cancer in acromegalic patients and to estimate possible factors influencing their occurrence, especially high IGF-1 level.

MATERIALS AND METHODS: 86 consecutive patients with acromegaly were retrospectively analyzed. 45 patients had been previously treated for acromegaly and 41 were newly diagnosed. In all subjects hGH, IGF-1, TSH, FT4 levels were determined. Thyroid gland was evaluated in ultrasound examination. Fine needle aspiration biopsy (FNAB) was performed in every solid or mixed thyroid nodule.

RESULTS: Thyroid morphology abnormalities were found in 75 patients (87.2%). 10 patients (11.6%) had diffuse goiter and 65 patients (75.6%) had nodular goiter. There were 5 cases of thyroid carcinoma (5.8%): 3 papillary carcinomas and two follicular variants of papillary cancer. Out of five cancers three were multifocal, one infiltrated thyroid capsule and one was diagnosed at the stage of metastases to four lymph nodes.

CONCLUSIONS: Our study confirmed common co-existence of acromegaly and thyroid lesions. Furthermore, it revealed considerably high occurrence of thyroid carcinoma in these patients. In view of this correlation, the potential role of IGF-1 in pathogenesis of benign and malignant thyroid neoplasms should be considered. Due to high frequency of thyroid cancer in acromegalic patients, we suggest to perform fine needle aspiration biopsy in each case of thyroid nodule.