[Panhypopituitarism revealing metastasis of small-cell lung carcinoma associated with sarcoidosis]

Pituitary metastasis and sarcoidosis are two causes of pituitary stalk thickening. Their association has been described ago three decades. In this setting, we report a case of panhypopituitarism revealing pituitary metastasis from a small-cell lung carcinoma associated with sarcoidosis. A 49 year-old smoking patient with type 2 diabetes was admitted for acute adrenal failure with polyuria polydipsia syndrome and a pituitary tumor syndrome. Hormone explorations confirmed anterior pituitary insufficiency. Water restriction revealed central diabetes insipidus. The hypothalamic-pituitary MRI revealed a 1-cm sellar mass with nodular thickening of the stalk. The chest radiograph showed a heterogeneous opacity in the left lung. The thoraco-abdominal scan demonstrated a mass in the left lung highly suggestive of malignancy and many enlarged mediastinal nodes, hepatic nodules, and hypertrophy of the left adrenal. Bronchoscopy was performed three times and showed infiltration of the left bronchial tree but histological examination of the bronchial biopsies was negative for all samples. Ultrasound-guided biopsy of the liver was achieved and histology demonstrated sarcoidosis. The diagnosis of sarcoidosis was incompatible with the deterioration of the patient's general status. Subsequent radiographic explorations showed an increase in the size of the tumor mass and histological evaluation of a scan-guided trans-thoracic biopsy demonstrated small-cell carcinoma. Small-cell lung carcinoma is the most common cancer with pituitary metastasis. The proposed link between sarcoidosis and malignancy has remained controversial but has not been proven false.