Pituitary tumours are often asymptomatic, and their finding is casual while performing a brain imaging test for another reason. The symptoms are associated with the size of the lesion, the relationship with the neighbouring structures, and hormone production. The symptoms can be divided into three groups:
Symptoms associated with the compression of neighbouring structures (mass effect). It depends on their size and location. They can present with headache, changes in the visual field due optic chiasm involvement (loss of the peripheral vision in both eyes), or double vision due to involvement of the nerves that control the movement of the eyes. They can occur in functioning and non-functioning adenomas.
Symptoms associated with hormone deficiency. Due to pressure on the health pituitary, the normal synthesis of pituitary hormones changes. The deficiency in any of these hormones may require replacement therapy, making it important to evaluate all the pituitary hormones when a pituitary tumour is found. This may cause tiredness, weight increase, decreased libido, changes in menstrual rhythm, mood changes… They can occur in functioning and non-functioning adenomas.
Excessive hormone production. This occurs in functioning adenomas. The symptoms are different depending on the hormone that is produced in excess.
Prolactinoma. It is the most common functioning adenoma. It is due to an increase in the secretion of prolactin. It is clinically manifested in women with a change in menstrual rhythm, galactorrhoea (spontaneous flow of milk from the breast) and a decrease in libido. In males it is associated with a decrease in sexual desire and erectile dysfunction.
Somatotropinoma. It is due to an excess in the production of growth hormone, and is the causing factor of acromegaly when it appears in the adult, or gigantism when it appears in infants (the growth cartilages are open). The symptoms can be very progressive, which can delay the diagnosis. The most characteristic are the gradual increase in the size of the hands, feet, and the jaw, with the appearance of coarse features (need to change shoe size, the rings or hats that fitted well before do not fit anymore…), growth of lips and nose, increased sweating, tendency to snore…
Thyrotropinoma. They are thyrotropin (TSH) producing adenomas, giving rise clinically to hyperthyroidism due to the excessive production of thyroxin. They are very uncommon.
Corticotropinoma. Also known as Cushing’s disease, and it is due to an excess in the production of corticotropin, or adrenocorticotropic hormone (ACTH). Clinically, affected individuals tend to gain weight, with rounded or “moon face”, appearance of dark-red stretch marks, high blood pression, diabetes, osteoporosis…