Category: Pituitary Disorders/Neuroendocrinology
Gonadotroph pituitary adenomas are one of the most common types of adenomas. They are mainly classified as nonfunctioning, or clinically ‘silent.’ Although about one-third secrete follicle stimulating hormone (FSH) and/or luteinizing hormone (LH), the secreted gonadotropins are considered to be inactive and do not have effect on sex hormones. Most of these adenomas are large ( >1 cm). Here we present a case of a gonadotroph microadenoma causing elevation in serum testosterone.
We report a rarely encountered case of a functional gonadotroph adenoma (FGA) causing clinically significant elevation of serum testosterone and performed a literature review
A 73 year old male with past medical history of hypertension, benign prostatic hyperplasia seen for the evaluation of elevated testosterone levels. Patient was following with a urologist for prostatic hyperplasia and elevated prostate specific antigen of 3.03ng/ml. He was having symptoms of urinary frequency, obstruction and nocturia, while on dutasteride. He was noted to have a total testosterone of 994ng/dl, with free testosterone of 109.3pg/ml. Luteinizing hormone was elevated for a male to 14.3 IU/L. Follicle stimulating hormone was also elevated to 14.6mIU/L. He had a normal testicular ultrasound. Thyroid stimulating hormone, free thyroxin, prolactin, insulin-like growth factor 1, AM cortisol, and adrenocortiocotropic hormone were all within normal limits. Pituitary MRI showed a local area of hypoperfusion along the inferior right aspect of the pituitary gland measuring 3mm, representing a pituitary microadenoma. Patient was started on spironolactone 25mg twice daily for antiadrogenic effect and also provided a referral for neurosurgery evaluation.
Gonadatroph adenomas cause increased levels of FSH/LH, but are considered to be inactive, rarely causing increased levels of peripheral sex hormones. There have been few reports of gonadotroph adenomas causing increased levels of estradiol causing ovarian hyperstimulation syndrome in females. Even more uncommon is gonadotroph adenoma causing excess of testosterone. Usually they are diagnosed by the symptoms secondary to mass effect of the pituitary mass, and are treated with transphenodial resection.
This is a presentation of a rare case of a functional gonadotroph pituitary adenoma (FGA) causing symptoms related to the elevated testosterone levels, rather than related to mass effect from a pituitary mass. It can be clinically difficult to diagnose with nonspecific symptoms, and often missed until they grow to macroadenomas causing compressive symptoms with high morbidity. FGA should be included in the differential of pituitary adenomas.
Brooklyn, New York
Endocrinology Fellow in the Division of Endocrinology, Northwell Health, Manhasset, New York