Endocrine Abstracts

Background: Anterior pituitary insufficiency or anterior hypopituitarism is a defect in the secretion of one or more of the pituitary hormones (ACTH, TSH, FSH and LH, GHand prolactin). It is a rare condition. A variety of diseases may be the cause, the most common being adenoma. In rare cases, it can be a clinical presentation of metastatic disease. Herein, we describe a case of a pituitary metastasis revealing a lung carcinoma in a 61-year old man.

Case report: A 61-year old man, with a history of heavy smoking and type 2 diabetes, was admitted with deterioration of general state. He reported constipation, anorexia, weight loss and decreased libido for 2 years and has stopped taking his insulin for 2 months because of hypoglycemic episodes. Examination showed psychomotor retardation, blood pressure (BP)at 106/62 mmHg, heart rate at 62 bpm, normal blood glucose and BMI of 32 kg/m². Ganglionic node palpation revealed several cervical, axillary and inguinal adenopathies. Laboratory tests found hyponatremia, lymphocytosis and elevated inflammatory markers. Colonoscopy was normal. Endocrine investigations revealed central hypothyroidism (TSH: 0.107 microUI/ml, FT4: 0.63 ng/dl) and hypocorticism (cortisol: 35 nmol/l), low testosteronemia at 0.081 ng/ml and hyperprolactinemia at 862 mUI/l. The patient was therefore started on hormonal replacement therapy (hydrocortisone and levothyroxine). Cerebral MRI found 4 metastases: right frontal, left parietal, sellar and suprasellar mass lesions isointense on precontrast T1 weighted, hyperintense T2 weighted and demonstrated predominately rim enhancement on FLAIR. Body scan was concordant with the diagnosis of pulmonary neoplasm with multiple secondary lesions (lymph node, bone, adrenal, cerebral, hepatic, pleural and peritoneal metastases), therefore classified T4N3M1c. Cervical ganglions biopsy confirmed the diagnosis of small cell pulmonary carcinoma. The patient was started on radiotherapy and was addressed to a specialized oncology center for follow up.

Discussion: Our report depicts an original and challenging diagnosis approach of small cell lung carcinoma revealed by pituitary metastasis with hypopituitarism. Pituitary metastases are uncommon. They represent 0.14 to 3.6% of all intracranial metastasis, and are rarely symptomatic (1% to 6%). In scarce cases, pituitary metastasis is the first manifestation of the cancer. Breast and lung cancer are the most frequent cause of pituitary metastasis. The association of infundibular metastasis and elevated serum prolactin has been reported.

Conclusion: Pituitary metastases may be the initial presentation of neoplasms or may occur during therapy. Physicians must be cautious, and must suspect the diagnosis when confronted with any sign that may suggest pituitary damage (hypothyroidism, adrenal insufficiency, etc.)