Pituitary Macroadenoma With Partial Transient Hypopituitarism

Abstract

Pituitary tumors are lesions of the central nervous system that are usually benign and most often develop sporadically. Non-functioning pituitary adenomas range from being clinically asymptomatic to causing significant hypothalamic/pituitary dysfunction, including hypopituitarism, and visual field loss due to their large size. Pituitary macroadenomas (size over 10 mm) may cause elevated prolactin levels (“pseudoprolactinoma”) as a result of the lost dopaminergic inhibition on pituitary lactotrophs. Spontaneous recovery of the pituitary function in patients with hypopituitarism after surgical removal of a macroadenoma is rare. We present a clinical case of a 40-year-old man, referred for diagnostic clarification in a specialized endocrine clinic, due to easy fatigue and swelling of the lower limbs and outpatient-acquired data on secondary hypothyroidism. From the conducted complex hormonal evaluation, the patient presented with partial hypopituitarism (secondary hypogonadism and hypothyroidism) and hyperprolactinemia. The performed magnetic resonance imaging (MRI) of the brain revealed a pituitary macroadenoma, measuring 24 × 23 × 22 mm, without involvement of the optic nerves. After the execution of transsphenoidal adenomectomy, the patient underwent recovery of the pituitary function and did not require permanent hormone replacement therapy. The described clinical case provides evidence of the unique high reparative and regenerative potential of the pituitary gland that should be kept in mind during the follow-up period of patients with postoperative hypopituitarism.