Ascites as the first manifestation of polyarteritis nodosa

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis that affects numerous organs, particularly the digestive tract (33-52% of cases). However, isolated ascites has rarely been described in patients with PAN. We observed a patient who had developed ascites revealing PAN, and because of suspected malignancy laparotomy and abdominal surgery were performed, including systematic total abdominal hysterectomy, bilateral salpingo-oophrectomy, submesocolic omontectomy and appendicectomy. Macroscopic examination revealed a nodule involving the left ovary, while histological examination of biopsy specimens demonstrated characteristic damage of necrotizing vasculitis involving the appendix, omentum, uterus, fallopian tubes and right ovary, consistent with PAN. The patient had a favourable outcome of clinical manifestations related to PAN after initiation of combined therapy of prednisone and cyclophosphamide. Our case report therefore reinforces the possibility of an unusual presentation of PAN. As ascites may precede other signs of PAN, we suggest that when unexplained ascites is noted an evaluation for misdiagnosed vasculitis should be carried out, including a search of the constitutional symptoms (e.g. fever, weight loss). Patients undergoing laparoscopy for peritoneal involvement of unknown origin should also have tissue specimens taken for pathologic studies, notably to exclude an underlying vasculitis.