Endocrine Abstracts

Background: Congenital obstructive hydrocephalus is rarely diagnosed in adulthood and may present with atypical endocrine manifestations. Pituitary stalk distortion or vascular compromise can result in hypopituitarism.

Case Presentation: A 25-year-old male with a history of ankylosing spondylitis presented with headache, fatigue, reduced libido, and diminished morning erections. He reported normal childhood development and pubertal onset at age 12, but minimal facial hair and difficulty growing a moustache. Initially, his libido was preserved, but over the preceding two years, he developed progressive loss of body hair, weight gain, gynecomastia, and loss of sexual drive.

Investigations: On examination, his height was 180 cm and BMI was 32.8. He had bilateral gynecomastia, normal testicular volume, and Tanner stage 5 secondary sexual characteristics. There were no overt signs of endocrinopathy. Biochemical evaluation revealed borderline low total testosterone (8.9 nmol/l; reference: 8.3–30), low LH (1.3 IU), and low FSH (0.9 IU), with normal cortisol, thyroid, and prolactin levels. Pituitary MRI demonstrated congenital obstructive triventricular hydrocephalus secondary to a fourth-ventricular web, with significant pituitary stalk distortion.

Management: Following multidisciplinary review, endoscopic third ventriculostomy with Rickham reservoir insertion was performed. Postoperatively, testosterone and gonadotropin levels remained low (total testosterone 8.5 nmol/l, calculated free testosterone 0.220 nmol/l, with persistently low LH 1.6 IU and FSH 0.7 IU). Initially, clomiphene or HCG therapy was discussed due to immediate plans for conception. Subsequently, after the patient confirmed fertility was no longer desired, testosterone replacement therapy was commenced.

Conclusion: This case demonstrates that congenital hydrocephalus may remain compensated until adulthood and present with endocrine dysfunction. It further highlights that vascular compromise to the hypothalamic-pituitary axis is likely the underlying mechanism, emphasising the importance of neuroimaging.