DIFFERENTIAL-DIAGNOSIS BETWEEN PREMATURE THELARCHE AND PRECOCIOUS PUBERTY FROM CLINICAL, HORMONAL AND RADIOLOGICAL DATA

In a retrospective study of 39 girls (aged 10 months to 710/12 years) with premature breast development criteria for distinguishing between premature thelarche and precocious puberty were analysed. Serum estrad iol levels and bone age were determined and a test with luteinizing ho rmone-releasing hormone (LHRH) performed (inclusion criteria). On the basis of the LHRH test and bone age, premature thelarche was diagnosed in 29 patients and precocious puberty in ten: while those with premat ure thelarche had a follicle-stimulating hormone (FSH) pattern of rise , in those with precocious puberty the rise in gonadotropin was of the LH type. The LH/FSH ratio 30 min after stimulation was < 1 (median 0. 15 [0.03-0.34] in patients with premature thelarche, but > 1 (median 2 .1 [1.34-5.67] in those with precocious puberty. Bone age was accelera ted by at least 18 months in those with precocious puberty, but it cor responded to their chronological age or was only slightly accelerated in those with premature thelarche. These data thus indicate that prema ture thelarche and central precocious puberty can be reliably distingu ished by the LHRH test and bone age.