Pituitary Tumors, Craniopharyngiomas, and Conditions Caused by them

Pituitary tumors arise from the pituitary gland within the base of the skull above the phayrnx (craniopharyngioma). These tumors are almost always benign in the sense that they do not generally fragment and travel to other locations in the body. Symptoms arise when these tumors secrete hormones or become large enough to compress adjacent structures. Rarely, these tumors may spontaneously hemorrhage.

As these tumors enlarge, the normal pituitary function is compromised or destroyed. This produces various hormonal conditions such as Cushing's syndrome, inappropriate lactation caused by a prolactinoma, or acromegaly which is also called giagantism due to oversecretion of growth hormone. Each of these are caused because the pituitary itself secretes hormones and they in turn control the action of other endocrine glands within the body.

Pressure on near-by structures can produces double vision and facial numbness. The nerves of vision, the optic nerves, are directly above the pituitary gland and upward growth of pituitary tumors frequently causes progressive visual loss. This visual loss is typically begins from each side of the field of vision leading to tunnel vision and then blindness if untreated.