Pituitary mass and subsequent involution causing fluctuations of serum follicle-stimulating hormone levels in a Turner syndrome patient with premature ovarian failure: a case report.

Background: Premature ovarian failure (POF) is described as estrogen deficiency, amenorrhea, and hypergonadotropinemia in a woman < 40 years old. In a proportion of patients diagnosed with POF, intermittent and unpredictable return of ovarian function can be observed, causing fluctuations of follicle-stimulating hormone (FSH). However, these patients also have return of menstrual cycles. When cycles do not resume, other causes could explain the changes in FSH levels.

Case: A 43-year-old woman with known premature ovarian failure since age 23 and high serum FSH levels was referred for normalization of FSH levels. She did not have any resumption of menstrual cycles. Karyotype revealed a mosaicism consistent with Turner syndrome. Computed tomography of the head detected a pituitary macroadenoma which is believed to have caused a decrease in FSH production by compression of the pituitary stalk. Spontaneous involution of the mass ensued, and the patient's serum FSH returned to menopausal level accompanied by an empty sella syndrome.

Conclusion: In menopausal patients with low FSH and no return of menstrual cycles, further investigations should be pursued in order to exclude a possible pituitary mass.