Evaluation of clinical and laboratory findings in the differential diagnosis of central precocious puberty and premature thelarche

Aim: In this study, it was aimed to examine the clinical and laboratory findings that can be used to predict central precocious puberty (CPP) in cases whose breast development started before the age of 8. Materials and Methods: The chronological age, anthropometric measurements, bone age (BA), hormone test results and pelvic ultrasonography findings of the cases were recorded. Those with a peak luteinizing hormone (LH) level of ≥5 IU/L in the gonadotropin-releasing hormone (GnRH) stimulation test were classified as CPP and those with a peak LH level of <5 IU/L were classified as prepubertal cases. A receiver operating characteristic (ROC) analysis was performed to determine the diagnostic accuracy of laboratory variables. Findings: A total of 297 female cases were included in the study. The age at the time of admission, height-standard deviation score (SDS), BA, the long axis of the uterus and the volumes of the right and left ovaries of the cases diagnosed with CPP were found to be significantly higher than those of the prepubertal group. The cut-off value providing the best sensitivity (99%) and specificity (99%) for the peak LH was found to be 4.55; the cut-off value providing the best sensitivity (94%) and specificity (85%) for the peak LH/follicle-stimulating hormone (FSH) ratio was found to be 0.32 and the cut-off value providing the best sensitivity (47%) and specificity (93%) for the basal LH was found to be 0.13. Conclusion: We believe that in female cases with early breast development, a peak LH level of ≥4.55 may possibly indicate CPP and a basal LH level of <0.13 can significantly rule out CPP.