ESPE Abstracts

Background: Since the late 1960’s, pubertal breast staging has been based on Tanner’s classification. Appearance of glandular breast tissue may be difficult to distinguish by palpation from the surrounding subcutaneous fat tissue, especially in obese girls. To our knowledge, validation of the clinical assessment of pubertal stages by MRI quantification of glandular breast tissue has never been performed.

Objective and hypotheses: i) To report normative data of glandular tissue volume in healthy girls. ii) Validate the clinical evaluation of pubertal breast staging by MRI of breast tissue. iii) Evaluate circulating hormone levels and morphology of internal genitalia by transabdominal ultrasound (TAUS) as markers of glandular tissue.

Method: Breast stage (Tanner B1–B5 by inspection and palpation) was performed in 121 healthy peripubertal girls from the Copenhagen Mother-Child Cohort (9.8–14.7 years). Glandular tissue volume was measured with MRI. Ovarian volume, follicle counts, uterine volume, and endometrial thickness were assessed by TAUS. Circulating levels of FSH, LH, inhibin B and oestradiol were assessed by immunoassays.

Results: Glandular tissue volume by MRI was positively associated with Tanner stages (r=0.858, P<0.001), however, marked inter-individual variation occurred in late puberty (B4+B5): median (range): 74 (20–241) cm³ and CV=51%. The sensitivity and specificity for breast palpation to detect the presence of glandular tissue using MRI as gold standard were 99 and 95%, respectively. The best parameters to distinguish between prepubertal girls (B1 and no glandular tissue on MRI) and girls with breast development (B2–B5 and visible glandular tissue on MRI) were: LH (area under the curve by ROC analysis=0.949), estradiol (AUC=0.935), FSH (AUC=0.879) and uterine volume (AUC=0.934), endometrial thickness (AUC=0.855) and ovarian volume (AUC=0.848).

Conclusion: Clinical palpation reliably detects glandular breast tissue. In addition, unstimulated LH, oestradiol, and FSH as well as uterine volume, endometrial thickness and ovarian volume are valuable to distinguish prepubertal from pubertal girls.