Thelarche Variant
This encompasses a spectrum of conditions, which lie between premature thelarche and central precocious puberty. It may be difficult to distinguish from central precocious puberty. Indeed, there is a complete spectrum of gonadotrophin secretion in these conditions between LH and FSH dominance. This condition has been described under different names, which has led to confusion. It has been known as unsustained precocious puberty, slowly progressive precocious puberty, thelarche variant and exaggerated thelarche. In all these conditions, there is a similar clinical description of breast development, which is similar to that seen in premature thelarche, although the breast cycling is less common.

There is usually pubic hair development, so that the condition cannot be classified as ‘isolated’ premature thelarche. However, the rate of growth is usually faster than normal, but without an advanced epiphyseal maturation. Growth prognosis appears to be normal, or near normal. The breast development frequently arrests and, certainly, does not advance to full sexual maturation. Behavioural problems are unusual. The condition only requires reassurance, but if treatment with a GnRH analogue is attempted, it may well result in a change of sexual maturation to central precocious puberty.

Patients with this condition of thelarche variant have often been included in patients with central precocious puberty and analysed contemporaneously in their response to GnRH analogue. As the growth prognosis is normal in the thelarche variant, it may well have compromised the analysis of patients with central precocious puberty and produced results which have suggested that GnRH analogue therapy produces an artificially improved benefit in terms of final height attainment. As this condition was only described a decade ago, there are no studies about the effect into adult life and longer-term studies will need to be undertaken.