A Rare Association of Autoimmune Hypophysitis With Seronegative Rheumatoid Arthritis: A Case Report

Autoimmune hypophysitis (AH) is an uncommon condition where there is inflammation of the pituitary gland which leads to hormonal imbalances. It is often associated with autoimmune diseases; however, a case is yet to be reported with an association of AH with seronegative rheumatoid arthritis (RA). We present a case of a 45-year-old female who complained of polyuria/polydipsia and rapid weight gain. An MRI of the head revealed enlargement of the pituitary gland, concerning for AH. Although she was initially treated for diabetes insipidus, she began reporting new complaints of joint pains and morning stiffness. She was clinically diagnosed with seronegative RA and improved with a trial of hydroxychloroquine. A repeat MRI showed improvement in the abnormal pituitary findings, and the patient was closely monitored with a multidisciplinary approach. Diagnosing and managing patients with AH are topics that are still being explored and researched as it is a relatively rare pathology. Consequently, we found the need to discuss the relationship of AH with seronegative RA and delve into the various diagnostic and treatment approaches.