A Diagnostic Scoring System to Distinguish Precocious Puberty from Premature Thelarche based on Clinical and Laboratory Findings

Background: The diagnosis of patients who present with early pubertal signs can pose a challenge. Objectives: The aim of this study was to design a new diagnostic scoring system based on clinical and laboratory findings to distinguish precocious puberty (PP) from premature thelarche (PT) among girls diagnosed with early puberty. Methods: We enrolled 267 girls (PP, n = 164; PT, n = 103) previously diagnosed with early puberty using GnRH test, retrospectively. A diagnostic scoring model (M) was constructed with five variables and their cut off values were determined for scoring: age of onset (6.5 years), bone age (BA)/choronologic age (CA) ratio (≥ 1.1), estradiol (12 pg/ml), uterine length (32 mm) and ovarian volume (1.09 cm3 ). Overall score was determined for model. The model was also applied prospectively to a second girls population (n = 86) that showed signs of early puberty. Results: The sensitivity and specificity of model was 89.6% and 87.4%, respectively. In the cohort group, the sensitivity and specificity of model was 90% and 89.4%, prospectively. Conclusions: A diagnostic scoring system, based on clinical and laboratory findings can be an alternative or complementary method for the differential diagnosis of early puberty.