Pituitary involvement in ANCA-associated vasculitis: Case report and literature review

The antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an rare autoimmune condition characterized by inflammatory cell infiltration causing necrosis of small blood vessels. Pituitary involvement is uncommon in AAV and it can occur at any point during AAV. The main clinical manifestations are central diabetes insipidus and panhypopituitarism. In this article, we describe 2 cases of pituitary involvement of AAV, pituitary dysfunction presented as initial symptom in 1 patient and developed over the course of the diseases in the other patient. Both of them had positive ANCA titers and myeloperoxidase positive antibodies. Two patients both had an enlarged pituitary, shown by magnetic resonance images, 1 patient also had Rathke's cleft cyst. After treatment with intravenous steroids, immunosuppressant, and biological agent, clinical symptoms as well as pituitary imaging were alleviated significantly. We go over a brief review of the currently available literature on pituitary involvement in AAV. The literature review identified 42.55% exhibited pituitary dysfunction at disease onset, commonly presenting with diabetes insipidus and deficiencies in pituitary hormones such as follicle-stimulating hormone-luteinizing hormone, thyrotropin, adrenocorticotropic hormone, and growth hormone. Beyond pituitary involvement, other organ lesions most frequently affect the ear, nose, throat, eye, pulmonary, and kidney systems. Pituitary magnetic resonance imaging was pivotal in lesion identification, frequently showing pituitary enlargement, sellar masses, and optic chiasm compression. The majority of patients achieved systemic disease remission or improvement during follow-up, although 52.17% continued to exhibit persistent pituitary dysfunction. The latest EULAR and KDIGO guidelines recommend glucocorticoids combined with immunosuppressive agents such as rituximab or cyclophosphamide for initial AAV treatment. Our cases demonstrated the effectiveness of early aggressive therapy with glucocorticoids combined with mycophenolate mofetil or rituximab in achieving disease remission and improving pituitary function.