Nonfunctioning and gonadotrophin-secreting adenomas

As nonfunctioning pituitary tumors and gonadotrophin-secreting adenomas likely arise from a similar cell type, they are often indistinguishable. These tumors are the second most frequently occurring tumors of the pituitary. They may immunostain and/or secrete gonadotrophins as well as subunits thereof. Macroadenomas tend to enlarge in 50% of cases within 5 years of diagnosis.
These are monoclonal tumors but the genetic basis is unclear. They may present incidentally or after some years with compression of the surrounding structures including visual field defects and headaches often associated with hypopituitarism.
Treatment is with surgery usually using the transsphenoidal route. After imaging and biochemical postoperative assessment, the usual treatment is with regular follow-up and imaging extended over a period of years. Radiotherapy may be necessary in the presence of persistent extrasellar tumor postoperatively.
Occasionally, these tumors present with more rapid growth but medical treatment with dopamine agonists or somatostatin receptor analogues is not usually useful. Temozolomide for aggressive tumors can be effective.
Gonadotrophin-secreting pituitary tumors may present with specific characteristics, including hyperstimulation of the ovaries in women, enlargement of the testes in men, and isosexual precocious puberty in children. In general, the treatment is similar to that of nonfunctioning pituitary adenomas.