Kallmann syndrome revealed by primary amenorrhea: Phenotypic variability and diagnostic challenges—A report of three cases

Kallmann syndrome is a rare form of congenital hypogonadotropic hypogonadism associated with anosmia or hyposmia. We describe 3 female patients aged 17, 17, and 22 years who were evaluated for primary amenorrhea and reported lifelong anosmia. Hormonal assessment demonstrated hypogonadotropic hypogonadism. Brain magnetic resonance imaging showed bilateral olfactory bulb agenesis in 2 patients and unilateral agenesis with contralateral hypoplasia in one. The clinical presentations varied: 1 patient had complete secondary sexual development, another had a maternal history of anosmia and delayed puberty, and the third had incomplete pubertal development with a borderline low morning cortisol level. Genetic testing was not performed. The combined clinical, hormonal, and imaging findings were strongly supportive of Kallmann syndrome. Treatment was individualized according to pubertal stage. These cases emphasize the value of systematic olfactory assessment and dedicated evaluation of the olfactory bulbs and sulci on magnetic resonance imaging in females with primary amenorrhea.