PRIMARY AMENORRHEA AND ANOSMIA IN A YOUNG WOMAN

A LATE DIAGNOSIS OF KALLMANN SYNDROME

Abstract

INTRODUCTION/BACKGROUND
Kallmann syndrome (KS), a genetic form of congenital hypogonadotropic hypogonadism (CHH), is characterized by delayed or absent puberty in combination with anosmia or hyposmia. It is more frequently diagnosed in males and often overlooked in females due to subtler clinical features. Underrecognition of anosmia and the absence of routine olfactory assessment contribute to diagnostic delays. Early diagnosis and hormone replacement therapy are essential for initiating pubertal development and supporting reproductive planning.

CASE
A 25-year-old female was referred for evaluation of primary amenorrhea and absent secondary sexual characteristics. She reported a lifelong inability to perceive odors. She was born full-term with no perinatal complications or congenital anomalies. Physical examination showed Tanner stage I breast and pubic hair development. Hormonal evaluation revealed low estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH), consistent with hypogonadotropic hypogonadism. Prolactin and thyroid hormones were within normal limits. Pelvic ultrasound revealed hypoplastic uterus and ovaries. Olfactory testing confirmed anosmia. Brain MRI demonstrated bilateral atrophy of the olfactory bulbs and non-visualization of the olfactory sulci, with normal pituitary anatomy. Bone mineral density (BMD) screening revealed osteoporosis. A diagnosis of Kallmann syndrome was established. Estrogen therapy was initiated, resulting in early breast development.

CONCLUSION
This case highlights the need to consider Kallmann syndrome in women presenting with primary amenorrhea, particularly when anosmia is present. Olfactory testing and neuroimaging are essential components of the diagnostic workup. BMD screening plays a crucial role in evaluating long-term complications of untreated hypogonadism. Timely hormonal therapy supports secondary sexual development, improves bone health, and may enhance psychosocial and reproductive outcomes.