Endocrine Abstracts

Introduction: Gynaecomastia (GM) is a major contributor to psychological morbidity in adolescent boys, yet there is a lack of evidence for effective treatment. It is known to develop due to the relatively higher diurnal oestradiol–testosterone ratio in early to mid puberty.

Aims: We retrospectively looked to identify possible criteria for the selection of patients to predict optimal management of GM. We also examined the effect on the persistence of GM of testosterone given for delayed onset/completion of puberty, but in reverse diurnal rhythm.

Methods: 16 patients had adolescent GM. We recorded age; BMI; Tanner G and B stages; testis volume; breast disc size; testosterone, oestradiol, FSH and LH blood levels; follow-up time; and if so any treatment received at each visit. When puberty was delayed, oral testosterone undecanoate (TU; Restandol) 40 mg was commenced, but in the morning increasing 6 monthly in order to counterbalance the rapid decline of testosterone levels in the afternoon/evening in the physiological diurnal rhythm of normal puberty and thus reduce the time of unopposed oestrogen exposure to the breast.

Results: We identified three groups with differing outcomes. Younger patients with lower BMI and smaller disc size required no intervention, as the GM resolved spontaneously. Patients with a higher BMI, larger disc size and smaller testis volume for their age benefited from intervention, and it was more effective on the group that also had low levels of testosterone at the start. Older, heavier patients, more advanced in puberty had less of a reduction of breast disc size despite the testosterone treatment.

Conclusions: We were able to outline criteria to predict the likelihood of success with reverse rhythm testosterone treatment. Younger patients with lower BMI and smaller disc size required no intervention. Patients presenting slightly older; with a larger disc size; with signs of delayed puberty and low testosterone levels may benefit from reverse rhythm TU to hasten resolution of GM. Patients with a particularly high BMI; large disc size; or presenting at a later stage in puberty are best referred directly for surgery.