An unusual cause of bleeding in primary hypothyroidism

A 10-yr-old female was referred due to prolonged bleeding lasting for a week following tooth extraction. She had heavy periods since she was 9. Her height was < 0.4th centile. Tanner staging was breast stage B3-4, axillary hair A1, and pubic hair P1. Thyroid function tests showed elevated TSH, low free T4, and negative anti-TPO antibodies. Gonadotrophins showed high FSH and a prepubertal LH. Prolactin was high and ovarian cysts were found on ultrasound. Further investigations revealed low von Willebrand factor (vWF) antigen levels, leading to a diagnosis of acquired von Willebrand disease. She was started on levothyroxine therapy, with normalization of vWF antigen levels, prolactin levels, cessation of her menstrual periods and resolution of ovarian cysts.