Lung Cancer Metastasis to the Pituitary Gland

Common sites of lung cancer metastasis include the bone, brain, liver, and adrenal gland. Cancer metastasis to the pituitary gland or sellar region is a rare finding. Here, we present a case of pituitary gland metastasis from underlying lung cancer in a patient presenting with a predominance of pituitary symptoms over respiratory symptoms. A 48-year-old female was admitted to the hospital with progressive visual deficits, intractable headaches, constant nausea and vomiting, fatigue, polyuria, and polydipsia for about three months, all consistent with pituitary symptoms associated with secondary adrenal insufficiency, secondary hypothyroidism, and central diabetes insipidus. A brain MRI done two months earlier revealed a large mass in the pituitary gland and sella turcica area. Biochemical test abnormalities consistent with pituitary hormonal insufficiencies were noted, and subsequent imaging showed an enlarging pituitary mass and extensive metastases to the bones, brain, liver, adrenal gland, and lymph nodes. Bone biopsy was consistent with poorly differentiated adenocarcinoma of the lung as the primary site. The young age of this patient is uncommon compared to most patients with pituitary metastasis. Worsening pituitary symptoms with an enlarging pituitary mass and widespread metastases should alert consideration for pituitary metastasis and a search for a primary cancer site. Pituitary metastasis portrays a poor prognosis.