Pineal region tumors: endocrinological aspects.

The pineal gland and the superior cervical ganglia represent an integration center for hormonal and neural signals, and play an important role in modulating basic hormonal secretions. The prevalence of pineal tumors in the male sex and their frequent association with precocious puberty has been known for a long time. However, the rarity of ascertained cases investigated by means of direct and sensitive methods (RIA; tests applying hypothalamic releasing factors) is still preventing the proper knowledge of the endocrinological aspects of pinealomas. On the basis of the recent literature, the importance of diabetes insipidus as a very early symptom of pineal region tumors should be emphasized; in some cases, it preceded the appearance of precocious puberty of neuro-ophthalmologic signs by some years. A variable pattern of anterior pituitary impairment is also a rather common finding. In rare cases (males, with few exceptions), the precocious puberty may be explained by the presence in the pineal tumor of trophoblastic tissue secreting hCG; some of these tumors produce also alpha-fetoprotein (evidence of a yolk-sac tumor).