The pituitary gland, or hypophysis (gr. “the growth which hangs below”) is a roughly spherical collection of hormone-producing tissues of the size of a pea. It lies in a bony protuberance in the base of the skull and is connected to the brain by a narrow bridge of tissue, the pituitary stalk.
The pituitary gland produces vitally important hormones, some of which act directly on target organs throughout the body while others have an effect on other hormone-producing glands. Important mechanisms ranging from growth to reproduction, as well as a host of metabolic functions, are controlled in this way.
Tumors affecting the hormone-producing cells in the pituitary are called adenomas. Pituitary adenomas are tumours, which arise from the various different cells of the anterior lobe of the pituitary gland and are nearly always benign (not cancerous).
Some adenomas can produce active hormones leading to elevated levels of these hormones in the blood. In other cases, the expanding adenoma can damage other, healthy hormone-producing tissue, leading to a reduction or even complete cessation of the production of some hormones. Depending on the type of hormone produced, hormone-producing adenomas of the pituitary gland produce a range of clinical syndromes, which can usually be diagnosed by a detailed panel of endocrine (hormone) blood tests. Some pituitary adenomas become large enough to put pressure on the optic nerves and can lead to visual problems.
To precisely diagnose pituitary adenomas, imaging with CT and MRI alongside opthalmological and endocrinological examinations is required. High resolution and spatial magnetic resonance imaging (MRI and MRA) and computer tomography (CT) is particularly useful in identifying the precise relationship of large blood vessels (such as the internal carotid artery), the optic nerves and other structures of the skull base to the tumour – these are critical steps in planning any operation which may be necessary.
The approach to treating pituitary adenomas must be carefully considered. Factors such as
must be investigated and weighed up. An operation is not necessary in all cases and some pituitary adenomas can be successfully treated with medications only.
If an operation is necessary, techniques are available to remove an adenoma precisely and with absolute minimum damage to healthy tissue. In every case, however, the surgery begins with thorough pre-operative planning. This includes taking high-resolution MRI and CT images of the tumour and its neighbouring structures and producing a detailed 3D reconstruction of the patient’s anatomy and the planned surgical approach.
Pituitary tumours can be treated using a minimally-invasive surgical approach through one nostril of the nose and the bone behind the nose, known as the sphenoid bone. This technique is called an endoscopic transsphenoidal approach.
In our clinic we have access to the most modern tools and equipment. The operation is performed using state-of-the-art endoscopic techniques and corresponding tube-shaft microinstruments in order to reach and remove the adenoma via a path through the nose and sphenoid sinus. During the approach through the nose we always work in collaboration with ENT (Ear Nose Thought) specialist surgeons.
A computer-aided navigation system enables precise surgery without explorative preparation of neighbouring healthy structures and an intraoperative MRI (PoleStar) allows us to constantly check the progress of tumour removal and ensure that, even in difficult to reach areas, a complete resection of the adenoma is made as easy as possible.
Before and after the operation a multidisciplinary team of endocrinologists and ENT surgeons is ensuring you get the best possible all-round care.
A 28-year-old female suffered from irregular menstrual cycle and loss of libido. Endocrinological evaluation revealed a moderately increased prolactin level of 68 ng/ml (normal value approx. 3 - 30 ng/ml) and mildly reduced levels of gonadotropins. MRI showed a pituitary macroadenoma of max. 18.4 mm in size with suprasellar growth (Fig. 1a,b), compression of the optic chiasm (the structure formed by the crossing of the optic nerves) and dorsal shift of the pituitary stalk.
An ophthalmological examination showed that there was no deficit of the visual field. Drug therapy with Dostimex (Cabergoline) rapidly normalized prolactin level, but in the course of nine months the size of the adenoma increased to 21.1 mm (Fig. 2a,b). Hence, it was proven that the adenoma was hormone-inactive. We established the indication for microsurgical tumor resection.
Endoscopic transsphenoidal surgery was performed through the right nostril. The entire adenoma was resected using three-dimensional navigation and endoscopic control.
The patient recovered very quickly and was discharged home three days after the operation. The pituitary hormone axes as well as the electrolytes were unremarkable. The postoperative sense of smell was fully intact.
The MRI after 3 months showed no evidence of residual tumor. The healthy pituitary gland showed to be positioned crescent-shaped at the back of the sella. The pituitary stalk was positioned in the middle (Fig. 3a,b).
The following endocrine investigations were unremarkable. Normalization of menstrual cycle and libido was achieved. The patient went back to work full-time as an accountant and enjoys mountain climbing as a hobby.