Pituitary tumours that produce prolactin in an uncontrolled way are referred to as prolactinomas. Prolactin controls among other things the production of milk and has an influence on the regulation of sexual hormones and thereby on the gonads (ovaries or testicles). Women complain of disturbances of menstruation, tension in the breast and galactorrhoea. In men there is a disturbance of libido and potency. Very large tumours can cause visual disorders.
Magnetic resonance imaging shows a contrast enhancing process of various sizes. The endocrinological diagnosis manifests a clearly increased prolactin level.
A: Small prolactinoma (arrows) in the pituitary gland region.
B: Gigantic prolactinoma with ingrowth in the brain.
In the case of prolactinomas usually at first a medication therapy with the so-called dopamine agonists, e.g. Pravidel (bromocriptine) or Dostinex (cabergoline), is carried out. Even in gigantic tumours a remarkable reduction of the tumour can often be achieved (Fig. 2). If the medication therapy is not successful or the medication is not tolerated due to adverse reactions, microsurgical complete tumour removal is again the therapy of choice.
The 13-year-old girl presented with visual field restriction, decline of acuteness of vision and oculomotor nerve palsy on the right side. In the subsequently carried out MRI one can see a gigantic contrast enhancing structure that starts from the skull base and stretches far to the interbrain. According to the MRI criteria this is a pituitary tumour. The hormone diagnostics showed strongly increased prolactin levels, so it turned out to be a prolactinoma. Despite the existing visual disorders surgery was not performed since the risks would have been increased due to the enormous tumour size. Instead treatment with dopamine agonists (Pravidel) was applied. Fortunately, the tumour rapidly reduced in size. One year after the Pravidel treatment the MRI shows a considerable reduction of the tumour size. The visual disorders resolved completely. The MRI 8 years after the Pravidel treatment reveals complete remission of the tumour. The other hormone axes are unimpaired.
Fig. 2. Macroprolactinoma
A: The MRI of 31.03.1993 shows a gigantic contrast enhancing structure that springs from the skull base and stretches up to the interbrain. The optic chiasma is completely suppressed by the tumour and cannot be isolated any more.
B: The MRI of 15.02.1994 under Pravidel therapy shows an excellent reduction in size of the tumour. There is only a small remaining tumour below the interbrain and in the region of the bony skull base.
C: MRI images of 05.01.2001 show complete remission of the tumour. One can recognize the pituitary stalk and the rest of the normal pituitary gland.
The 18-year-old girl presented with amenorrhoea. In the MRI images one can detect a contrast enhancing tumour that displaces the normal pituitary gland to the left. The prolactin level in blood was considerably increased. Prolactinoma was diagnosed and treated appropriately with dopamine agonists (Pravidel). However, the tumour did not reduce in size, but grew bigger. As a result of that the indication for endoscopic-assisted microsurgical tumour removal was made, and the tumour was removed via the right nostril. The postoperative MRI images one year after the surgery show complete removal of the prolactinoma with a fully preserved normal pituitary gland. The endocrinological tests showed the normalization of prolactin levels and normal performance of the remaining hormone axes.
Fig. 3. Microprolactinoma
A: The MRI shows a small structure in the pituitary fossa that displaces the normal pituitary gland to the left.
B: The postoperative MRI shows complete tumour removal. The prolactin levels became normalized. The pituitary gland works properly. Hormone replacement is not necessary.