Swyer syndrome

Spontaneous menstruation has been reported in people with Swyer syndrome.^[1] While people with Swyer syndrome typically have functional female genitalia and structures including a vagina, uterus and fallopian tubes, they typically do not have ovaries and are therefore infertile.^[2] For this reason, they ordinarily do not produce sex hormones and will not undergo puberty (including starting menstruation) unless treated with hormone replacement therapy.^[2] In most cases, Swyer syndrome is not diagnosed until the early teens because a girl with Swyer syndrome does not start her period (primary amenorrhea).^[2] However, there have been a few reports in the medical literature of girls with Swyer syndrome having spontaneous menstrual cycles.^[1]

It has been suggested that normal pubertal development (including spontaneous menstruation) in people with Swyer syndrome may be associated with the presence of a hormonally active tumor.^[1] It has been reported that both male and female sex steroids may be produced by gonadoblastoma and that gonadoblastoma is often the source of hormones in females with an 46,XY karyotype.^[1] Gonadoblastoma is a benign tumor but it has the potential for malignant transformation (turning cancerous). Having Swyer syndrome is a known risk factor for the development of this type of tumor. Spontaneous menstruation due to neoplastic estrogen secretion in general has also been reported.^[1]