Highlight On Management Of Pituitary Gland Tumors

Abstract

Pituitary tumors are common in the general population. In 16.7% , changes in the pituitary gland can be detected . Since neuroimaging techniques have recently improved, pituitary tumors are more frequently diagnosed incidentally. Usually, pituitary tumors are assigned as primary tumors of the central nervous system(CNS) and contribute to 5% to 20% of all primary CNS tumors . In 95% of cases, pituitary tumors occur sporadically. Only in 5% may a familial genetic background be assumed, e.g. as part of Multiple Endocrine Neoplasia (MEN) Type 1, Carney’s Complex (CNC), or Familial Isolated Pituitary Adenomas (FIPAs). In most cases, pituitary tumors are benign adenomas. Pituitary carcinomas are extremely rare, and in these cases the assumption is that they are former benign adenomas that have undergone additional genetic mutations . Pituitary adenomas are classified partially depending on their size into microadenomas (<1 cm) and macroadenomas (>1 cm). The size of the adenoma corresponds with compromising effects on the optic chiasm, cranial nerves, and cavernous sinuses, but tumor size does not reflect its clinical importance . This classification is supplemented by immunochemistry and functional status. Pituitary tumors are classified as functioning or non-functioning on the basis of their ability to produce and secrete mature hormones . Approximately half to one third of all pituitary tumors are non-functioning pituitary adenomas (NFPAs) (i.e. without hormone secretion detected either by immohistochemistry or by elevated hormonal blood levels). Conclusion 121 The most common hormone-secreting pituitary tumor is the prolactinoma (lactotroph adenoma – 25%-41%), followed by somatotroph adenomas (10%- 15%), corticotroph adenomas (about 10%), thyrotroph adenomas (<1%), and gonadotroph adenomas (<1%) . Pituitary tumors are mostly monoclonal. Therefore, genetic influences in only one cell might induce tumor transformation. Since magnetic resonance imaging (MRI) techniques have improved and are used more widely in the general population, pituitary adenomas are more frequently diagnosed incidentally. Pituitary tumors such as NFPA might not be identified for many years. In contrast, macroadenomas can cause local symptoms such as visual disturbances when the optic chiasm is compressed. Even small pituitary adenomas might have clinically important consequences through elevated hormonal levels and become apparent as hyperprolactinaemia, GH, or cortisol excess. In these patients, endocrinological disturbances can lead to secondary hypogonadism due to hyperprolactinaemia, acromegaly, or Cushing’s disease (CD).