Endocrine Abstracts

Introduction: Hypopituitarism can be caused by a number of different etiologic factors including metastatic cancer. Metastasis to the pituitary gland is rare, accounting for only 1.8% of all metastases, and is often detected incidentally by symptoms associated with hormone dysfunction like hyponatremia. Breast and lung cancer are the primary neoplasms with well established properties of pituitary infiltration. Metastases from gastric cancer are unusual and constitute less than 2% of pituitary gland metastases.

Case study: 37-year-old woman with 7-month history of gastric cancer (adenocarcinoma tubulare without HER2 amplification), treated with capecitabine, epirubicin, and oxaliplatin based chemotherapy formulation was admitted to the ER due to persistent headache and nausea. Laboratory results revealed hyponatremia (125 mmol/l) and pancytopenia presumably due to chemotherapy. During admission she complained of generalized fatigue and was hypotensive. She had a history of secondary amenorrhea. She was admitted to Endocrinology Department to conduct differential diagnosis of hyponatremia. Laboratory work-up revealed panhypopituitarism with low ACTH, cortisol, TSH and free thyroid hormone levels as well as decreased prolactin, gonadotrophin and IGF-1 concentrations. Diabetes insipidus was absent and the function of the posterior lobe of the pituitary gland was preserved. MR imaging confirmed the pituitary involvement showing a 35×15mm mass infiltrating sella turcica and suprasellar cistern. She received hydrocortisone and L-thyroxine hormone replacement therapy with significant improvement of her clinical status (stabilization of blood pressure, correction of hyponatremia), and was referred to Oncology Department for further treatment.

Conclusions: Hypopituitarism due to pituitary metastasis is a rare complication of gastric cancer. The possibility of pituitary metastasis should always be considered in patients with malignant tumors, who present with hyponatremia or other symptoms suggestive for endocrine dysfunction. The early diagnosis and introduction of appropriate hormone replacement therapy treatment improves the quality of life and can possibly prolong survival.