Body size measurements, digit ratio (2D:4D) and oestrogen and progesterone receptors' expressions in juvenile gigantomastia.

Background Juvenile breast hypertrophy is characterised by massive enlargement of the breast in the peri-pubertal period. We aimed to analyse body size measurements (body mass index [BMI], waist-to-hip circumference ratio [WHR]), digit ratio (ratio of II and IV digits' length [2D:4D]) and oestrogen receptor (ER) alpha (ERα) and progesterone receptors (PRs) in the breast gland in women with juvenile gigantomastia. Methods The study involved 30 women (mean age 25.7 years) (mean age of onset - 14.8 years). ERα and PR expressions were detected immunohistochemically in breast gland samples. For comparison, 100 controls (50 women and 50 men) were included. Results BMI and WHR in women with gigantomastia were higher than in control women and the former had a higher WHR than expected for their BMI. 2D:4D in the examined women did not differ from that in control women. However, left 2D:4D was negatively related to the age of gigantomastia onset. There were no correlations between ER and PR expressions and the analysed body and digit ratios. Conclusions The lack of a relationship between 2D:4D and juvenile breast hypertrophy may suggest that foetal exposure to sex hormones may not be crucial in its aetiology. However, the link between high left 2D:4D and early development of gigantomastia suggests that prenatal sex hormones have a role in its development timing. High WHR, and particularly high WHR relative to BMI, may indicate that these women had at some stage of development higher circulating androgens, which may have been converted to oestrogens in breasts due to local aromatase activity. Verification of this hypothesis could allow consideration of the role of aromatase inhibitors in juvenile breast hypertrophy.