Hormone-active intradural spinal metastasis of a prolactinoma — A case report

Summary A 44-year-old woman developed acute severe visual field defects and was operated on a macroprolactinoma. Since complete resection of the tumor was not possible, radiotherapy was performed and in addition to hormone replacement therapy, bromocriptine (up to 60 mg daily) was started without however complete normalization of PRL levels. Four years later PRL levels increased to 10⁵ µU/ml despite continuation of dopamin agonist (mesulergin) treatment. As shown by ophthalmological examination and computer tomography there were no signs of regrowth of the pituitary tumor. At that time the patient complained of severe lumbar pain and myelography revealed a tumor mass in the spinal cord (L₁–L₂). Since the spinal tumor was not removable, laminectomy was performed. Histology and immunohistochemistry demonstrated a metastasis of the prolactinoma. Radiotherapy and bromocriptine in extreme doses (140 mg daily) together with an antiestrogen were not able to improve the neurological deficits (paraparesis) and to lower the PRL levels. This case of a metastasis of a prolactinoma after operation, radiotherapy, and dopamin agonist treatment stresses the importance of close surveillance of patients with prolactinomas without PRL normalization during dopamin agonist therapy and shows for the first time the possibility of ectopic PRL production due to an intradural spinal metastasis.Abbreviations ACTH adrenocorticotropin - FSH folliclestimulating hormone - GH growth hormone - Gy Gray - L lumbar - LH luteinizing hormone - µU/ml microunits per milliliter - mU/ml milliunits per milliliter - PRL prolactin - TBG thyroxine-binding globulin - TSH thyrotropin - T₄ thyroxine - T₃ triiodothyronine