An Incidental Pituitary Adenoma with intact LH Hypersecretion

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Objective: We present a relatively uncommon case of gonadotroph cell adenoma with elevated FSH and intact LH resulting in supranormal free and total testosterone. Case Presentation: A 52 year old Caucasian male with a history of hypertension, diabetes mellitus, normal pubertal and fertility history presented with head trauma due to assault by his son. He did not have any focal neurological deficit on initial presentation. CT of the head incidentally showed a large rounded mass measuring 4.1 x 4.3 x 6.3 cm. Brain MRI showed a large sellar and suprasellar mass extending to the right anterior cranial fossa with surrounding vasogenic edema. Imaging was most suspicious for a pituitary macroadenoma. His initial labs were FSH 58.3 mIU/mL (0.9-15), LH 9.1 mIU/mL (1.5- 9.3), prolactin 25.3 ng/mL (1.8-14.4), free testosterone 29 ng/dL (7.2-24) and total testosterone 837 ng/dL (193-740). LH was confirmed to be intact by immunoassay. TSH and ACTH were normal, but GH was 0.1 ng/mL (0-6.0) and IGF-1 was 59 ng/mL (87-238). The patient underwent image guided transnasal, transsphenoidal resection of the tumor, right frontotemporal craniotomy and orbital osteotomy for resection of the supratentorial component of the tumor. Pathology returned as pituitary adenoma with expression of only FSH and LH. His postoperative course was complicated by intracranial hemorrhage and Enterobacter encephalitis, eventually requiring tracheostomy and PEG tube placement. Post resection labs showed LH <0.1 mIU/mL, FSH 2.2 mIU/mL, testosterone <3 ng/dL, prolactin 7.4 ng/mL, TSH 0.009 uIU/ML, free T3 0.2 pg/mL, and free T4 0.07 ng/dL. His pituitary insufficiency was treated with methylprednisolone and levothyroxine. Secondary hypogonadism was treated with testosterone gel. The most recent free T4 was 0.7 ng/dL, free T3 1.7 pg/mL and testosterone 139 ng/ dL. His neurological status gradually improved and was discharged to a long term rehabilitation center. Discussion: Many patients who have gonadotroph cell adenomas are often middle aged males with normal pubertal development and fertility history. They are brought to medical attention because of visual impairment due to the size of the adenoma. The most common hormonal characteristic of gonadotroph cell adenomas is hypersecretion of FSH and less often by hypersecretion of intact LH. Our patient had an adenoma hypersecreting intact LH resulting in supranormal testosterone levels. Conclusion: This unique case describes an incidental pituitary adenoma with intact LH hypersecretion, whereas the vast majority of pituitary adenomas have impaired LH secretion.


Pituitary Disorders, Abstract #909.


Endocrinology, Diabetes, and Metabolism | Internal Medicine


Department of Medicine, Department of Medicine Faculty

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