Thyroid Diseases in Patients With Pituitary Neuroendocrine Tumours

Due to the hypothalamic-pituitary-thyroid axis, thyroid disease is often associated with pituitary neuroendocrine tumours (PitNETs). However, the associations across different PitNETs subtypes remain underexplored. This study investigates the characteristics of thyroid disease in patients with different PitNETs subtypes and evaluates the impact of PitNETs treatment on thyroid disease.

A retrospective analysis was conducted on 168 patients with PitNETs who were categorised into 3 groups: GH (n = 53), PRL (n = 65) and NF (n = 50). All patients underwent thyroid ultrasonography, pituitary tests and thyroid function tests before treatment and 1 year after treatment.

Thyroid volume was significantly larger in the GH group (30.78 ± 7.87 mL, p < 0.01). The incidence of thyroid goitre and nodules was markedly higher in the GH group (73.58%, p < 0.01; 54.17%, p < 0.01), with a significantly higher proportion of multiple thyroid nodules in the GH group (79.31%, p < 0.01). Autoimmune thyroiditis was more common in PRL group (18.46%, p = 0.04), associated with elevated TPOAb (169.63 ± 325.28 IU/mL, p = 0.02) and TGAb antibody levels (236.23 ± 379.91 IU/mL, p = 0.02). One-year postoperative follow-up, the postoperative thyroid volume decreased from 23.45 ± 8.99 mL to 20.42 ± 6.48 mL (p < 0.01). The incidence of thyroid goiter decreased from 36.90% to 13.10% (p < 0.01). In patients with autoimmune thyroiditis, TPOAb and TGAb levels decreased significantly after treatment (p = 0.01, p < 0.01, respectively).

Increased thyroid volume, goiter and multiple nodules are prevalent in GH-PitNETs patients, while autoimmune thyroiditis predominates in PRL-PitNETs. Treatment of PitNETs alleviates these thyroid manifestations. Routine thyroid ultrasound monitoring is recommended for PitNETs patients.