Prevalence of thyroid cancer in patients with acromegaly and non-growth hormone secreting pituitary adenomas: A prospective cross-sectional study

Objective

To evaluate the prevalence of differentiated thyroid cancer (DTC) in patients with non-GH secreting pituitary adenomas [NGHPA group: non-functioning (NFPA), prolactin (PRL) and corticotropin (ACTH)-secreting adenomas] compared to patients with acromegaly, a pituitary disease that has been associated with increased risk for thyroid cancer.

Patients and methods

Prospective, cross-sectional study involving consecutive outpatients followed in our institution with diagnosis of acromegaly (n = 71; 43 women, median age 57 yrs) and NGHPA (n = 57; 38 women, median age 48 yrs.; PRL (n = 35), ACTH (n = 7), NFPA (n = 15). All participants were subjected to thyroid ultrasound (US) by the same examiner, and US-guided fine needle aspiration (FNA) biopsy when indicated.

Results

Thyroid volume was higher in acromegaly than in NGHPA (median 12.5 ml vs 6.3 ml; p < 0.0001), and thyroid nodules were present in 27/71 (38.0%) of acromegaly patients and in 14/57 (24.6%) of NGHPA group. FNA was indicated in 15/27 (55.5%) of acromegaly patients [Bethesda I (n = 1); II (n = 11), III (n = 1), two patients refused FNA], and in 8/14 (57.1%) of the NGHPA group [Bethesda I (n = 2); II (n = 4); V (n = 1); VI (n = 1)]. The two patients of NGHPA group with Bethesda V and VI were operated and papillary carcinoma was confirmed histologically.

Conclusion

DTC was not detected in our acromegaly patients and its presence in patients with NGHPA suggests that DTC predisposition is not related to GH excess.