Endocrine Abstracts

Introduction: Autosomal dominant polycystic kidney disease (ADPKD) is an inherited kidney disease characterized by the development and growth of cysts causing a progressive kidney enlargement and the end-stage renal disease (ESRD). The incidence of brain aneurysms in patients with ADPKD is high thus screening is recommended. The association of pituitary incidentalomas and ADPKD is rarely described in the literature. All reported pituitary adenomas in patients with ADPKD were functional growth hormone (GH) secreting adenomas. We represent a rare case of macroprolactinoma in a patient with ADPKD and ESRD.

Case presentation: A 43-year-old male with ADPKD and ESRD, treated with chronic haemodialysis, was referred to a Magnetic Resonance Imaging (MRI) of the head as a part of the pre-transplantation evaluation. The MRI scan showed the sella turcica filled with an enlarged pituitary gland protruding cranially into the suprasellar cistern, raising and shortening the infundibulum, and reaching the lower contour of the optic chiasm and nerves. The pituitary gland had total dimensions of 21 x 12 x 17 mm (CC x AP x LL). The patient was referred to an endocrinologist, and a laboratory examination was performed. The results were as follows: elevated prolactin level > 4255.3 mIU/l (n.r. 56.0 - 278.4), low FSH 0.88 IU/l (n.r. 1.27 - 19.26) with LH 4.99 IU/l (n.r. 1.24 - 8.62), total testosterone 8.22 nmol/l (n.r. 5.21 - 23.70), sex hormone binding globulin 26.8 nmol/l (n.r. 13.3 - 89.5) and free testosterone 185 pmol/l (n.r. 170 – 660). The function of thyrotropic, corticotropic and somatotropic cells was normal. The patient did not complain of mass effect symptoms, such as a headache or visual field disturbance, and his visual field examination was normal. He had no symptoms of hypogonadism and was a father of one child. A diagnosis of a prolactin-secreting pituitary macroadenoma (macroprolactinoma) was made and the bromocriptine therapy was started. After two months, the prolactin level was normalized (175.6 mIU/l; n.r. 56.0 - 278.4), together with the FSH level. The bromocriptine therapy was continued, while the check-up pituitary MRI is planned 6 months after the initiation of the therapy.

Conclusion: Hyperprolactinemia is a common endocrine abnormality in patients with the kidney failure, most often not requiring a specific treatment. This case report highlights that a patient with the kidney failure and extremely high prolactin levels, especially if accompanied with a headache or visual field disturbance, needs to be examined for a prolactinoma.