Recognition of Rare, Atypical Manifestations Is Important for Diagnosis and Management of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: Comment on the Article by Delaval et al.

I read with great interest the article by Delaval et al. They reported the largest case series of temporal arteritis in ANCA-associated vasculitides (TA-AAV), showing their clinical, serological, and histological manifestations [1]. Recent progress in understanding AAV have revealed that AAV can present rare, atypical manifestations such as isolated dacryosialadenitis, isolated retroperitoneal fibrosis, and isolated hypertrophic pachymeningitis [2-4]. Therefore, in such cases, it is important to recognize AAV as one of the differential diagnosis and to conduct histological examination and ANCA testing for appropriate management of the disease. I would ask the questions for further clarification of the study of TA-AAV.