Ultrasonography of Ovary, Uterus and Breast in Premature Thelarche

We studied 17 girls with the complaint of premature breast development. Enlarged breast tissue was confirmed in 15 patients by sonography. Pelvic and breast sonography were also performed in these patients. The sizes of most uteri and ovaries were within the normal range. Nine of the 15 patients (60%) showed follicular cysts in the ovaries. These cysts were ovoid with diameters of up to 10 mm. No relationship was found between the thickness of breast tissue and the ovarian findings. Pelvic sonography was also performed in normally developing girls under 6 years of age. Four of 47 girls (4%) showed small follicular cysts in the ovaries. In summary a high percentage of patients with premature thelarche have relatively large follicular cysts, with normal sized ovaries and uteri. Breast sonography is useful to distinguish swollen subcutaneous tissue from breast development.