Gonadotropin-secreting pituitary tumor associated with hypersecretion of testosterone and hypogonadism after hypophysectomy.
OBJECTIVE
To review gonadotropin-secreting pituitary tumors and report the rare case of one of these tumors that caused high serum testosterone concentrations, followed by hypogonadism after hypophysectomy.


METHODS
A case report is presented of a 61-year-old man who had decreased vision in his left eye, found by computed tomography of the sella to be attributable to a soft tissue pituitary mass with upward extension that caused elevation and deviation of the optic chiasm. Endocrine and pathologic evaluations are presented, and the treatment and follow-up course are discussed.


RESULTS
Endocrine evaluation revealed a serum follicle-stimulating hormone (FSH) of 72.48 mIU/mL, luteinizing hormone (LH) of 31.65 mIU/mL, prolactin of 26.42 ng/mL, and total testosterone of 15.24 ng/mL (all values higher than the normal ranges). A soft tissue mass (3.2 by 2.5 by 1.2 cm) with negative immunocytochemical staining for prolactin and growth hormone but positive staining for synaptophysin, FSH, and LH was removed. One month postoperatively, the patient's chief complaints were a decrease in penile size and erectile dysfunction. Endocrine evaluation revealed a decreased LH of <0.3 mIU/mL, total testosterone of <0.2 ng/mL, and FSH of 4.3 mIU/mL. Three months later with testosterone replacement therapy, testosterone levels normalized, LH was <0.3 mIU/mL, and FSH was 3.9 mIU/mL. Thyroid function and adrenal function were normal before and after surgical intervention.


CONCLUSIONS
This rare case indicates that gonadotropin tumors can produce a functional LH that can increase serum testosterone levels.
Department of Internal Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of South Florida Medical School and James A. Haley Veterans Hospital, Tampa, Florida 33612-4798, USA.
Michelle N
MN
Dizon
David L
DL
Vesely
D005640:Follicle Stimulating Hormone / Q000032:analysis / Q000097:blood; D006062:Gonadotropins / Q000378:metabolism*; D019382:Human Growth Hormone / Q000032:analysis; D006801:Humans; D007006:Hypogonadism / Q000209:etiology*; D007016:Hypophysectomy; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000032:analysis / Q000097:blood; D008279:Magnetic Resonance Imaging; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000601:surgery; D011388:Prolactin / Q000032:analysis / Q000097:blood; D016708:Synaptophysin / Q000032:analysis; D013739:Testosterone / Q000097:blood / Q000378:metabolism*; D014057:Tomography, X-Ray Computed
D006062:Gonadotropins; D016708:Synaptophysin; D019382:Human Growth Hormone; D013739:Testosterone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone