Characteristics of Male Prolactinoma and Problems in Management

Abstract

Seven male cases with prolactinsecreting pituitary adenomas were studied. The mean age was 29.4 years (range: 19 to 34 years). All had visual impairment, decreased libido/impotence, and lessened general body hair. Plain X-ray films of the skull and sellar tomograms revealed destruction of the sella turcica and upper clivus in all cases. Marked suprasellar extension of the tumor was noted in 5 of 6 patients who underwent pneumoencephalography. Endocrinological evaluation disclosed hyperprolactinemia (≥ 2,000 ng/ml) in all cases. Other pituitary hormones were measured in 6 cases. Subnormal or absent GH reserves were evidenced by the lack of response to insulin induced hypoglycemia in 6. FSH and LH were measured before and after stimulation by 100 μg of LH-RH iv. Three of 6 patients had normal responses in each, one for FSH/LH, a second for FSH, and the rest for LH. On the other hand, normal or above normal responses of TSH to 500 μg of TRH iv. were noted in all cases. Urinary 17-OHCS were of subnormal levels in 3 of the 7. Plasma testosterone, measured in 3, were all of low values. In two who had small testicles it was impossible to induce erection and ejaculation, and one of the two showed delayed puberty. The third patient, who was able to ejaculate, had azoospermia. Six of 7 patients undertook transsphenoidal surgery, and the subfrontal approach was performed in one. None of them became normoprolactinemic postoperatively. Therefore, all patients needed bromocriptine administration (10 to 15mg/day) to decrease serum prolactin levels. Remarkable reduction of pituitary tumor size after treatment with bromocriptine was observed in one patient. Bromocriptine was withdrawn because of side effects in one patient who complained of visual disturbance 2 months later. Reoperation was performed and pituitary carcinoma was found. Cerebrospinal fluid rhinorrhea associated with symptoms of pituitary apoplexy was observed in one patient before surgery, who was treated with bromocriptine. It was probably due to regression of the tumor. Loss of libido/impotence after surgery were successfully managed with additional treatment of human chorionic gonadotropin (HCG) injections. © 1982, The Japan Neurosurgical Society. All rights reserved.