Panhypopituitarism in a Patient with Breast Cancer.

Background: Malaise and fatigue are common symptoms of advanced malignant disease. Nevertheless, a specific cause - requiring specified treatment - for this symptom should be ruled out. We report on a patient with a complex endocrine dysfunction that developed due to a tiny metastasis of a breast carcinoma in the pituitary stalk. Case Report: A 46-year-old woman presented with general ill feeling 3 years after operation for a breast carcinoma. She was diagnosed to have hepatic and peritoneal metastases and malignant pleural effusion. For the application of chemotherapy, an i.v.-port system in the right brachiocephalic vein was inserted. In the postoperative period, an emergency situation developed due to demasked cortisol deficiency and hypernatremia. Careful laboratory investigations revealed hypofunction of the anterior lobe of the pituitary gland and diabetes insipidus centralis. By MRI imaging of the parasellar region, a 4 x 5 mm metastatic lesion in the pituitary stalk was found - notable only in knowledge of the clinical diagnosis. The patient's condition and quality of life improved markedly with hormone replacement therapy. Conclusion: Metastatic cancer may present as endocrine disease, either by release of hormone-like substances or by tumorous destruction of endocrine structures. Metastases of solid tumors to the pituitary gland are often asymptomatic or present with diabetes insipidus. The presentation with a hypofunction of the anterior and posterior lobe of the pituitary gland is a rare event. It is recommended to consider endocrine dysfunction as potential cause of 'malaise' in a cancer patient.