**Part 2**

**Pituitary Adenomas** 

22 Contemporary Aspects of Endocrinology

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actinomorphy in Bournea (Gesneriaceae). New Phytol. 2008 178:532-543.

relating to the floral developmental transition from initial zygomorphy to

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**2** 

*Italy* 

**The Genetics of Pituitary Adenomas** 

Monica Fedele, Giovanna Maria Pierantoni and Alfredo Fusco

*di Biologia e Patologia Cellulare e Molecolare, Università di Napoli Federico II* 

*Istituto di Endocrinologia e Oncologia Sperimentale (IEOS) del CNR, and Dipartimento* 

Cancer is considered a disease of the genome since the development of the vast majority of the human neoplasias is due to the accumulation of gene mutations. Indeed, the vast majority of tumours occur due to a considerable number of mutations that human cells accumulate during lifetime. Approximately 380 genes, representing about 1% of all human genes, have been implicated *via* mutation in tumorigenesis (Futreal et al., 2004). Most (90%), of these mutations are somatic, whereas germline mutations are a minority (20%). Some

Pituitary adenomas (PA) are one of the most frequent intracranial tumours with a prevalence of clinically-apparent tumours close to one in 1,000 of the general population and are the third most common intracranial tumour type after meningiomas and gliomas (Scheithauer et al., 2006). The majority of pituitary adenomas are sporadic and only a small subset (5% of all pituitary tumours) are familial, and often occur as component of familial endocrine-related tumour syndromes. Despite their benign nature, PA can cause significant morbidity because of hormonal hyper-secretion, or compressive effects to surrounding tissues. For example, GH-producing adenomas are associated with a GH excess that leads to gigantism or acromegaly, depending on whether the excessive GH occurs prior or not to epiphyseal-plate closure, respectively. In addition, if the pituitary mass overgrows, it can impinge upon the optic chiasm interfering with vision or generally results in headache due

Therefore, molecular understanding of pituitary adenoma formation is essential for the

The pituitary gland, also known as hypophysis, is one of the most important glands of the mammalian endocrine system. Through its secreted hormones, it controls the growth and activity of other glands: the thyroid, the adrenals, the gonads, the liver, the adipose tissue and the mammary glands (Fig. 1). The pituitary does not act independently, but it is under the continuous control of the nervous system through the hypothalamus. A wide range of external stimuli, including supply of nutrients, the ambient temperature, the exercise, and physical or psycological stress, causes secretion of hypothalamic hormones. As a response to hypothalamic control, the pituitary secretes the hypophyseal hormones, which maintain

development of medical therapies and the treatment of post-operative recurrences.

mutations may be both somatic and germline (10%) (Futreal et al., 2004).

to the increased pressure on the surrounding brain structures.

**1. Introduction** 

**2. The pituitary gland** 
