The Interdisciplinary Management of Newly Diagnosed Pituitary Tumors

Background: The increasing use of cranial tomographic imaging has led to the more frequent discovery of pituitary tumors. In this review, we discuss the clinical symptoms that point toward a pituitary tumor, the required diagnostic studies, the potential need for follow-up studies, and the indications for neurosurgical treatment.

Methods: This review is based on pertinent publications from the years 2005-2020 that were retrieved by a selective search in PubMed, as well as on the current German S2k guideline, which was created with the present authors playing a coordinating role, and on further guidelines from abroad. Relevant information from older reviews was also considered.

Results: The reported prevalence of pituitary tumors varies depending on the method of data acquisition. Autopsy studies yield a figure of 10.7%, while population-based studies reported 77.6-115.6 cases per 100 000 inhabitants. These lesions are nearly always benign, and 85% of them are pituitary adenomas. Pituitary adenomas measuring less than 1 cm in diameter are called microadenomas, while those measuring 1 cm or more are called macroadenomas. According to magnetic resonance imaging (MRI) studies, the prevalence of microadenomas in the general population is in the range of 10-38%, while that of macroadenomas is 0.16-0.3%. Pituitary adenomas can be either hormonally inactive or hormonally active. Half of all patients with hormonally inactive microadenomas display no endocrine abnormality, while 37-85% of patients with hormonally inactive macroadenomas manifest at least partial pituitary insufficiency. The clinical spectrum of pituitary tumors ranges from a fully asymptomatic state to visual disturbances, neurologic deficits, severe hormone excess (e.g., in Cushing disease), and life-threatening pituitary insufficiency. Pituitary adenomas are often diagnosed only after a latency of many years, even when they are symptomatic. If an imaging study shows the tumor to be in contact with the visual pathway, an ophthalmological evaluation should be performed. There are clear indications for surgery, e.g., imminent loss of vision, but most asymptomatic pituitary tumors can be observed only.

Conclusion: The manifestations of pituitary tumors are first recognized by primary care physicians. The further diagnostic evaluation of these patients should be carried out in standardized and interdisciplinary fashion.