Hypophysitis with adrenal insufficiency secondary to immune checkpoint inhibitors therapy

Background: Checkpoint inhibitors are monoclonal antibodies with action against solid and hematologic neoplasia with increasing use, which is why there have been reports of adverse events including endocrine system compromise. We report the case of a patient treated with anti PD-1 who developed an endocrinopathy. Purpose: To present the case of a patient with an endocrinopathy (hypophysitis) with secondary adrenal compromise associated with the use of checkpoint inhibitor therapy in a clinic in the city of Medellín, Colombia. Case presentation: 75-year-old male patient with a history of poorly differentiated squamocellular carcinoma of the lung, without lymphovascular invasion, treated with nivolumab, who after 6 months of treatment seeks consultation due to abdominal pain and several emetic episodes. On physical examination, the patient was hypotensive, and hypotonic hyponatremia was documented with decreased morning and afternoon cortisol. A pituitary profile was requested, showing decreased ACTH, prolactin, and luteinizing hormone with a normal TSH. Additionally, a sella turcica MRI was performed without evidence of structural damage, which is why it was concluded to be hypophysitis with a secondary adrenal insufficiency. Discussion and conclusion: Checkpoint inhibitor therapy offers a great advance in cancer treatment, and its increasing use allows us to watch and describe its adverse effects, making it possible to understand its mechanisms and possible risk factors. This is the first case of hypophystis secondary to anti PD-1 alone without CTLA-4 reported in the country. It is important to consider the possible adverse effects that patients undergoing immunotherapy treatment may experience, and to have a high index of clinical suspicion to perform appropriate tests for early identification.