A Case of Unusual Initial Presentation of Panhypopituitarism From Metastatic Adenocarcinoma of Lungs

Introduction: Metastatic disease of the pituitary gland account for about 1 to 2 percent of the sellar masses with suprasellar extension. Approximately 7 percent of the patients are symptomatic with varying symptoms based on the location and extent of metastases. We present you a case in which patient presented with features of Panhypopituitarism starting with severe hypothyroidism in a previously undiagnosed lung cancer. The Patient also suffered with some serious complications such as diabetes insipidus, adrenal insufficiency and complete vision loss. Clinical Case: A 60 y/o male with a past medical history of Hypertension, Chronic Obstructive Pulmonary Disease, smoking 2 packs of cigarettes per day for 40 years, second-degree heart block requiring a pacemaker, Chronic kidney disease 3b presented to the emergency department with complaints of left ankle pain, swelling, and syncope. The Patient was admitted for further workup and Endocrinology was consulted for concerns of hypothyroidism with severe myxedema and adrenal insufficiency. CT head was done, which showed sellar and suprasellar mass lesion measuring 1.8 x 2.2 x 3.0 cm. Finding were confirmed on MRI. Pertinent labs were PTH 57.7 pg/ml, TSH 0.33 uIU/ml, Free T4 0.4 ng/dl, ACTH 8 pg/ml, Cortisol 2.5 ug/dl, FSH 0.5 MIU/ml, LH 0.1 MIU/ml, testosterone 4 ng/dl, Prolactin 17.7 ng/ml, Insulin-like GFBP-3: 2.1 mg/L. The Patient was started on high dose Hydrocortisone, IV Levothyroxine T4 and desmopressin for Diabetes Insipidus. The Patient complained of peripheral vision loss. Neurosurgery partially resected the sellar mass through the transsphenoidal approach. Histopathology came back with Metastatic adenocarcinoma. Further clinical course was complicated by complete vision loss from increase in the sellar mass size after 8 weeks. Patient received radiation therapy but unfortunately there was no significant improvement in the vision. Conclusion: This case highlights some serious complication from metastatic disease of Pituitary gland from lung cancer. There is a need for continued annual screening for dysfunction of the hypothalamic-pituitary axis to monitor therapy. This case also highlights the importance of widespread screening of smokers in accordance with the standard lungs cancer screening recommendations. This can potentially prevent some of the serious complications of metastatic lung disease. Reference: Ross, D. Cooper, D. Mulder, J. (2020, September) Central Hypothyroidism. https://www.uptodate.com/contents/central-hypothyroidismSnyder, P. Cooper, D. Martin, K. (2020, September) Causes, presentation, and evaluation of sellar masses. https://www.uptodate.com/contents/causes-presentation-and-evaluation-of-sellar-masses