ESPE Abstracts

Introduction: In the rare aromatase excess syndrome aromatase turnover from androgens to estrogens is constitutively increased. Affected males show signs of hyperestrogenism such as feminization (particularly gynecomastia), hypogonadism, and short adult height due to early epiphyseal closure.

Case report: Here, we report the different statural growth of two first degree cousins affected by aromatase excess syndrome. Both carried the same heterozygote deletion of the regulatory part of the aromatase gene explaining the phenotype. Only one cousin was treated with an aromatase inhibitor before puberty started. Cousin 1 was the index patient of the family and presented at an age of 13 years because of bilateral gynecomastia (Tanner stage B4). Bone age was advanced by 2 years. He went for surgical mastectomy and was only seen aged 18 years due to incomplete virilisation. His adult height was 162 cm (−2.15 SDS) and his target height was 165 cm (mother’s height 145.7 cm due to aromatase excess syndrome). At that time the diagnosis was made based on a pathologically low testosterone to estradiol ratio, and low–normal LH and FSH levels. Treatment with an aromatase inhibitor (testolacton 5 mg/kg per day for 1 year, then anastrozole 1 mg/day for 1 year) improved virilisation, but no further gain in height could be reached. Cousin 2 presented at the age of 9 years with unilateral breast development (Tanner B2) and accelerated bone age. He showed elevated estrone levels and was immediately diagnosed with aromatase excess syndrome because of his relationship to cousin 1. Treatment with anastrozole 1 mg orally was given and he already reached a normal adult height of 175 cm at the age of 15 years (0.75 SDS). His target height was 171 cm.

Conclusion: These two cases illustrate the potential of aromatase inhibitors to effectively prevent short stature in aromatase excess syndrome.