NFAs, frequently macroadenomas, usually present with signs as a result of local mass effect and extension outside the sella turcica. Symptoms are bitemporal hemianopsia, decreased visual acuity, ophthalmoplegia and signs and symptoms as a consequence of hormonal insufficiency. Loss of vision due to NFA is caused by compression of the optic system and results in visual field defects in 85% and in complete blindness in 2% of NFA-patients8. Ophthalmoplegia is caused by invasion of the tumour in the cavernous sinus, compressing the third, fourth and sixth cranial nerve.
Hypopituitarism due to pituitary adenoma is caused directly by destruction or compression of normal pituitary tissue or indirectly due to compression of the pituitary stalk or of the portal circulation with focal necrosis of normal pituitary tissue as a result11. The prevalence of hypopituitarism is largely restricted to macroadenomas12. Features of pituitary insufficiency include decreased libido and/or erectile dysfunction in men, irregular menses or amenorrhea in premenopausal women, and fatigue (thyroid hormone, cortisol, GH deficiency or deficiencies).
Secreting pituitary adenomas are in general smaller than NFA at the time of diagnosis, because their symptoms are based on excessive hormone production.
Prolactinoma with its hypersecretion of prolactin in women can result in irregular menses or amenorrhea, galactorrhea and loss of libido. In men, loss of libido and impotence is observed.
With GH excess, leading to the syndrome of acromegaly, features develop insidiously over decades, often resulting in a delay of 5 to 10 years in diagnosis after the estimated onset of symptoms. Symptoms are enlargement of the acra (facial bones, hands and feet), paresthesias, excessive sweating, arthropathy, headache, tiredness, and sleep apnoea.
Cushing’s disease is caused by ACTH overproduction and characterized by weight gain, centripetal fat distribution, fatigue, memory loss, irritability, depression, muscle weakness, osteoporosis and purple striae.