A case of Kallmann syndrome associated with a non-functional pituitary microadenoma

Summary

Kallmann syndrome (KS) is a form of hypogonadotropic hypogonadism in combination with a defect in sense of smell, due to abnormal migration of gonadotropin-releasing hormone-producing neurons. We report a case of a 17-year-old Tunisian male who presented with eunuchoid body proportions, absence of facial, axillary and pubic hair, micropenis and surgically corrected cryptorchidism. Associated findings included anosmia. Karyotype was 46XY and hormonal measurement hypogonadotropic hypogonadism. MRI of the brain showed bilateral agenesis of the olfactory bulbs and 3.5 mm pituitary microadenoma. Hormonal assays showed no evidence of pituitary hypersecretion.

Learning points:

• The main clinical characteristics of KS include hypogonadotropic hypogonadism and anosmia or hyposmia.

• MRI, as a non-irradiating technique, should be the first radiological step for investigating the pituitary gland as well as abnormalities of the ethmoid, olfactory bulbs and tracts in KS.

• KS may include anterior pituitary hypoplasia or an empty sella syndrome. The originality of our case is that a microadenoma also may be encountered in KS. Hormonal assessment indicated the microadenoma was non-functioning. This emphasizes the importance of visualizing the pituitary region in KS patients to assess for hypoplastic pituitary malformations or adenomas.