Endocrine Abstracts

Introduction: Pituitary tumors are the most frequent intracranial neoplasm. However metastases in this location are rare and uncommon presentation of systemic malignancy. The clinical and radiologic features of most pituitary metastases can be characteristic and evocative but in no case pathognomic. The diabetes insipidus is the most common clinical manifestation of the disease. We report here four cases of pituitary metastases of lung cancer in an elderly patients mimiking pituitary apoplexy.

Observations: Case 1: A 69-year-old patient active smoker with history of type 2 diabetes mellitus presented with signs of acute adrenal insufficiency; vomiting, low blood pressure and hypoglycemia and polyuro polydipsic syndrom. Assessment of pituitary function revealed hypopituitarism and an insipidus diabetes; serum cortisol level of 12.6 ng/ml, Free T₄ level of 6.8 pg/ml, TSH level of 0.005 mUI/ml, total testosterone level of 0.025 ng/ml, FSH level of 0.5 IU/ml, luteinizing hormon level of 0.1 IU/l and low urine osmolarity. A hormone replacement therapy was indicated urgently. A magnetic resonance imaging (MRI) was demonstrated an inhomogeneous pituitary hypertrophy, appearance of central necrosis, with convexity of the sellar diaphragm, a nodular thickening of the pituitary stalk, and a loss of high intensity signal from the posterior pituitary. In front of the deterioration of the general condition, tobacco intoxication, the imagery founds and the very high level of carcinoembryonic antigen (CEA) at 197 μg/l, the computary tomography scan (CTS) of the Chest, Abdomen and Pelvis was performed and revealed a mass in the upper right lobe with mediastinal lymph nodes, liver and bilateral adrenal metastases.

Case 2 and 3: 72 and 68 year-old patient were admitted for pituitary apoplexy in MRI. Assessment of pituitary function revealed hypopituitarism and an partial insipidus diabetes. In front of weight loss, tobacco intoxication, the level of CEA (150 and 178 μg/l), chest-X-Ray abnormalities, hypothalamic and pituitary metastasis was suspected. The CTS scan revealed a mass in the lung with mediastinal lymph nodes, and bilateral adrenal masses. In all cases, a biopsy confirmed lung cancer. A specific treatment was planned.

Conclusion: Despite the fact that pituitary metastasis are rare, they must be evoked on the presence of pituitary apoplexy and sudden pituitary involvement associated to diabetes insipidus,, even in the absence of a neoplastic history. Pituitary tumor and / or metastasis should be taken in account in differential diagnosis.