Pelvic ultrasonography: Early differentiation between isolated premature thelarche and central precocious puberty

Abstract

We examined 55 girls with isolated premature thelarche between the ages of 0.3 and 7.4 years (group A), 20 children with central precocious puberty between 2.1 and 7.7 years of age and 101 age-matched controls. The children with precocious puberty were divided according to distribution of pubic hair into group B (Tanner stages PH1, B2-3; n = 11), representing an early stage of the disorder, and group C (stages PH2-3, B3-4; n = 9), representing an advanced stage. Uterine and ovarian volumes were measured sonographically, peak serum levels of luteinizing hormone and follicle-stimulating hormone were determined after intravenous administration of luteinizing hormone-releasing hormone. The mean uterine and ovarian volumes were significantly greater in children with precocious puberty than in controls (group B: uterine volume: 3.8 +/- 2.0 ml vs 0.9 +/- 0.3 ml for controls, P < 0.001; ovarian volume: 2.2 +/- 1.3 ml vs 0.6 +/- 0.2 ml for controls, P < 0.01; group C: uterine volume: 8.0 +/- 4.4 ml vs 1.0 +/- 0.3 ml for controls, P < 0.01; ovarian volume; 2.6 +/- 1.3 ml vs 0.4 +/- 0.1 ml, P < 0.01). No significant differences were found between children with premature thelarche and the control group. As a diagnostic method for the early detection of central precocious puberty, ultrasound measurement of uterine volume had a sensitivity and specificity of 100% (cut-off value, 1.8 ml), while ultrasound determination of ovarian volume had a sensitivity of 82% and a specificity of 95% (cut-off value, 1.2 ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasonographic and clinical parameters for early differentiation between precocious puberty and premature thelarche

“…In agreement with others (29), we found most of the sonographic parameters to be highly specific in differentiating PP from PT, but insufficiently sensitive: Uterine volume O1.96 ml had a sensitivity of 88.8% and specificity of 89.4%, compared to the 100% sensitivity and specificity reported by Haber et al (11). Corresponding values for uterine transverse diameter O1.5 cm were 68% and 100%.…”

“…In addition, some of the earlier studies used pubertal response to the GnRH stimulation test as a diagnostic criterion for PP (25,26), creating a possible preselection bias (26). The GnRH test has a low sensitivity (11)(12)(13), perhaps because the transition to a LH-predominant response is often a relatively late development in the clinical progression of PP (12). Also, there is no agreement as to the LH cut-off for diagnosis of PP (20,27,28).…”

“…The GnRH stimulation test is considered the gold standard for diagnosis. Yet, despite its high specificity, its sensitivity is low (11)(12)(13), and researchers disagree as to which response to GnRH stimulation should be used for diagnosis of CPP.…”

Ultrasonographic measurement of ovarian volume in the diagnosis of central precocious puberty

“…Therefore, either the described means or the cutoff values must be incorrect. Because the cut-off values are far above the values of 1.2 cm 3 and 1.0 cm 3 described previously 3,4 , we suppose that the reported means and SDs are correct. So, using the area under a standard normal curve we estimated new cut-off values for ovarian volume that would provide a sensitivity of 80%.…”

“…For example, for the age interval of 0-6 years they reported a cut-off value for ovarian volume of 3.04 cm 3 , above which the described sensitivity in identifying CPP was 100%. However, the mean value described for girls with CPP at this age interval was 2.62 cm 3 , so the sensitivity using the cut-off of 3.04 cm 3 was probably lower than 50%. We therefore calculated the estimated sensitivities and specificities for uterine length and volume, ovarian volume and F/C based on the area under a standard normal curve using the reported means and SDs for each parameter ( Table 1).…”