Gonadotroph adenoma of the pituitary gland: a clinicopathologic analysis of 100 cases.

OBJECTIVE

To determine the clinical and pathologic features in a large cohort of randomly selected patients with gonadotroph pituitary adenomas.

DESIGN

We retrospectively reviewed clinical, surgical, and pathologic findings in 100 patients (79 men and 21 women, 30 to 82 years old) with this tumor.

RESULTS

Diagnosis of a pituitary tumor was prompted by visual loss (43%), symptoms of hypopituitarism (22%), headache (8%), or a combination of these findings (10%); 17% of the patients were asymptomatic. Visual field defects were present in 68% of the study group, and complete or partial anterior pituitary failure was present in 77%. Serum prolactin concentrations were increased (maximum, 110 ng/mL) in 33% of patients. Hypersecretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) was documented in 11 and 5 patients, respectively. The serum level of alpha-subunit was increased in 1 of 29 patients in whom it was measured. All patients had pituitary macroadenomas, only 21% of which were grossly invasive. The surgical approach was transsphenoidal in all but two patients, who underwent transfrontal craniotomy; gross total tumor resection was achieved in 90%. By definition, all tumors had at least 10% immunoreactivity for LH, FSH, or both. All tumors were chromophobic. Ultrastructurally, the tumors were characterized as gonadotroph adenomas of "male" (45%) or "female" (9%) type as well as null-cell adenomas of the oncocytic (35%) or nononcocytic (11%) type. After a median follow-up of 4.3 years, 69% of the patients who had had visual field defects noted normalization or improvement. Persistent or clinically recurrent pituitary tumor tissue was present in 42%. A second pituitary surgical procedure was required in eight patients.

CONCLUSION

Most patients with clinically evident gonadotroph pituitary tumors have loss of vision and hypopituitarism. Hypersecretion of FSH or LH is unusual, and no distinct hormone-dependent clinical phenotype is present. Transsphenoidal surgical treatment generally yields normalization or improvement of visual field defects.