Related Experiment Video
Updated: Jul 2, 2026

Endoscopic Endonasal Trans-sphenoidal Approach: Minimally Invasive Surgery for Pituitary Adenomas
Published on: January 17, 2018
Primary hypothyroidism in a child simulating a prolactin-secreting adenoma
Crésio Alves1, Ana Cláudia Alves
1Pediatric Endocrinology, Faculty of Medicine, Universidade Federal da Bahia, Rua Plinio Moscoso, 222/601, CEP: 40157-190, Salvador, Bahia, Brazil. cresio.alves@uol.com.br
Objects:
To report a case of primary hypothyroidism associated to hyperprolactinemia mimicking a prolactin secreting adenoma.
Materials And Methods:
A girl (10 years and 10 months old) was evaluated for hyperprolactinemia (prolactin: 317 ng/mL [1.9-25]). Diagnostic evaluation demonstrated free thyroxine (F-T4): 0.22 ng/dL (0.75-1.80) and thyroid-stimulating hormone (TSH): 135 UI/mL (0.3-5.0). Pituitary magnetic resonance imaging (MRI) showed an intrasellar and suprasellar mass measuring 1.9 x 1.7 x 1.7 cm, impinging on the optic chiasm. Due to the possibility of a pseudoprolactinoma caused by hyperplasia of the TSH and prolactin-producing cells, she was treated for the primary hypothyroidism with levothyroxine. After 2 months, F-T4, TSH, and prolactin returned to normal values. A new pituitary MRI, 8 months later, demonstrated a complete resolution of the pituitary mass confirming the initial suspicion of thyrotroph hyperplasia.
Conclusion:
This paper illustrates the importance of thyroid function investigation in patients with hyperprolactinemia and possible prolactinoma in order to avoid unnecessary surgery.
Related Concept Videos
Hyperthyroidism I: Introduction
Hypothyroidism II: Pathophysiology
Hyperthyroidism II: Pathophysiology
Major Hormones and Their Functions
Oxytocin, produced in the hypothalamus and released by the pituitary gland, plays a role in social bonding, childbirth, and lactation.
Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
Goiter

