Prolactinoma

Periodic measurement of serum prolactin.

Initially, pituitary magnetic resonance imaging is recommended every year (more frequently in macroadenomas or in patients where serum prolactin continues to rise despite dopamine agonist treatment). The frequency of imaging can reduce once there is suppression of serum prolactin into the normal range and a stable tumour remnant.

Regular visual field examination (perimetry) is required in patients with visual field disturbance secondary to optic chiasmal compression, until maximal improvement is achieved. Patients with macroprolactinomas should also have regular perimetry to monitor for development of new field defects suggesting tumour growth and optic chiasmal compression.

In patients with macroprolactinomas, pituitary hormone axes (testosterone, thyroid function tests) should be assessed every 3-6 months if hypopituitarism is treated with hormone replacement (thyroid hormone, glucocorticoids, testosterone/oestrogen). Hypopituitarism may sometimes resolve with successful tumour shrinkage by a dopamine agonist.

Patients using high-dose cabergoline for a long time should be monitored by echocardiography for the rare adverse effect of valvulopathy.