Ultrasonic morphology of uterus and ovaries in girls with pituitary hyperplasia secondary to primary hypothyroidism.

We aimed to study uterine and ovarian morphology, hormonal levels, and pituitary height in prepubertal girls with pituitary hyperplasia secondary to primary hypothyroidism (PH) before and after thyroid hormone replacement therapy. We investigated 24 prepubertal girls with severe PH who were divided into 2 groups: secondary pituitary hyperplasia (group A, n=18), without pituitary hyperplasia (group B, n=6). Serum levels of free triiodothyronine (FT3), free thyroxine (FT4), thyrotropin (TSH), follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), testosterone (T) and prolactin (PRL), pituitary height, uterine volume (UV), ovarian volume (OV), follicular diameter (FD), and follicular number (FN) in group A were measured before and 3-month after levothyroxine therapy. Age-matched healthy prepubertal girls (control group, n=30) were also enrolled in the study. The levels of FT3 and FT4 were significantly lower and the values of TSH, FSH, E2, PRL, pituitary height, UV, OV, and FD were significantly higher in group A than in the control group (all p<0.05). In group B, FT4 levels were significantly lower and TSH levels were significantly higher than in the control group (both p<0.05); the values of FSH, E2, PRL, UV, OV, and FD tended to be higher than those in the control group; there were no statistically significant differences (all p>0.05). After 3-month of therapy, hormonal levels regressed and imaging abnormalities decreased. Our results indicate that PH patients with pituitary hyperplasia have enlarged uterus, ovaries and follicles, as well as high values of FSH, E2, PRL, and pituitary height, which are improved after levothyroxine therapy.