Endocrine Abstracts

Background: Constitutional delay of growth and puberty (CDGP) is the commonest cause of delayed puberty in boys and differentiation of CDGP from other causes of delayed puberty can sometimes be challenging. We report a boy with delayed puberty due to a pituitary adenoma.

Case: A 15-year-old boy was referred for endocrinology consultation with concerns regarding short stature and delayed puberty. There was no history or laboratory evidence suggestive of chronic illness. The tanner pubertal staging showed A1P2G2 with testicular volumes of 4 ml on the right and 3 ml on the left side. The glucagon stimulation test that performed at the referring hospital showed a peak GH of 4.3 μg/l and the GnRH test showed a peak LH of 11.6 U/l. A repeat primed glucagon stimulation test showed a peak GH of 2.07 μg/l confirming GH deficiency. He was commenced on growth hormone therapy. An MRI scan revealed the presence of a pituitary lesion (2×1.5×1.7 cm), which was slightly displacing the optic chiasma. A formal ophthalmology examination did not show any visual abnormality. Further investigations showed a normal Synacthen test, normal thyroid function, and a slightly elevated prolactin at 475 pmol/l (0–350). The lesion was removed by transphenoidal surgery and the biopsy confirmed pituitary adenoma. There was no progression of puberty 6 months after the surgery suggesting hypogonadotropic hypogonadism and testosterone therapy was commenced.

Conclusion: Non-functioning pituitary adenomas are rare in adolescence. Although the most common cause of delayed puberty in boys is CDGP, this is a diagnosis of exclusion. Detailed history, physical examination, auxology, bone maturation, biochemistry, and MRI based on clinical findings may be necessary to exclude other causes of hypogonadism.