ACROMEGALY, DIABETES-INSIPIDUS, AND VISUAL-LOSS CAUSED BY METASTATIC GROWTH HORMONE-RELEASING HORMONE-PRODUCING MALIGNANT PANCREATIC ENDOCRINE TUMOR IN THE PITUITARY-GLAND - CASE-REPORT

The case of a 52-year-old woman with acromegaly, diabetes insipidus, a nd visual impairment caused by a metastatic growth hormone-releasing h ormone (GRH)-produced pancreatic tumor is reported. Serum growth hormo ne (GH) and somatomedin C levels were elevated to 14 ng/ml (normal <5 ng/ml), and 3.20 U/ml (normal <1.88 U/ml), respectively. Paradoxical i ncreases were observed in GH levels after glucose tolerance and thyrot ropin-releasing hormone-stimulation tests. Biopsy of a pituitary tumor observed on computerized tomography scans and magnetic resonance stud ies revealed a metastatic cancer. When circulating GRH levels were mea sured, a marked increase in plasma GRH (1145 pg/ml; normal <4-1 pg/ml) was observed. The patient died of cachexia due to metastases. Postmor tem examination revealed that a primary tumor, a malignant endocrine l esion, was present in the pancreas, with metastatic tumors in the pitu itary, lung,liver, and adrenal glands. Synthesis and production of GRH by the tumor was demonstrated by Northern blotting and immunohistoche mical analysis. The pituitary gland showed hyperplastic, but not adeno matous changes. The authors stress the importance of both exploration for an ectopic source of GRH and the search for a GH-producing pituita ry adenoma when unusual signs and symptoms are seen in patients with a cromegaly.