Introduction: Functioning gonadotroph adenomas (FGA) are adenomas secreting and expressing biologically active gonadotropins and causing distinct clinical manifestations. The vast majority of the immunohistochemically confirmed gonadotroph adenomas are hormonally silent (presenting only with mass effects), clinically FGAs being very rare; whereas their exact prevalence is not known.
Case study: A 46 years old male patient presents to our clinic after being diagnosed with pituitary macroadenoma on MRI scan. The scan was made for elucidating the cause of cluster type of headache, symptom that appeared 4 years prior to the investigation. The contrast MRI scan showed a 37/34/24 mm expansive mass located intra-, supra-, and infrasellar, going in the sphenoidal sinus. General examination revealed symptoms like headache and increased libido, while the signs showed right facial muscle spasm and macro-orchidism (approx. 45 ml). Blood test showed polyglobulia (RBC=6.70*106/μl, Hb=17.9 g/dl, Hct=55.6%) and increased levels of FSH (145.4 mIU/ml), LH (23.2 mIU/ml), Testosterone (>1500 ng/dl), Estradiol (152.8 pg/ml). We recommended surgical intervention for the macroadenoma. Histopathology slides made by hematoxylin and eosin staining revealed a proliferation of cuboidal-columnar and oval cell with a fine chromatin nucleus, eosinophilic cytoplasm, arranged in a trabecular, papillary and perivascular pattern, with the reticulin network disorganized at tumoral level. Immunohistochemical testing found positive result for chromogranin A, FSH and LH with a Ki 67 of 4%. The patient presented 3 months after surgery for postoperative evaluation. On the follow up contrast MRI scan no tumoral rest was detected, the head ache was gone but the facial muscle spasm remained. The patient accused a lack of libido and a decrease in testicular size (in present approx. 30 ml). The CBC returned to normal, the FSH dropped to 1.6 mIU/ml, LH to 1.12 mIU/ml, Testosterone to 23.05 ng/dl and Estradiol to 5 pg/ml. After a Dipherelin 0.1 mg (triptorelin) stimulation test FSH and LH levels remained the same at 4- and 24-hour testing. We started testosterone replacement therapy.
Conclusion: This is a rare case of functioning gonadotroph adenoma treated surgically. The 46 years old patient is now suffering gonadotropin insufficiency for which he receives testosterone replacement therapy.
Keywords: functioning gonadotroph adenomas, testosterone
18 - 21 May 2019
European Society of Endocrinology