[Nodular and granulomatous form of periarteritis nodosa caused by the hepatitis B virus].

Polyarteritis nodosa (PAN) is, in rare cases, associated with subcutaneous nodules and pathology does not usually show the presence of peri and extravascular granulomas. When present in patients with hepatitis B virus (HBV) related PAN these facts demonstrate that classification of PAN is not homogeneous. CASE REPORT. A patient infected by HBV developed a PAN demonstrated by clinical symptoms and pathology. The disease was characterized by the presence of subcutaneous nodules and histologically by peri- and extra-vascular granuloma which surrounded necrosis of medium-sized vessels. Outcome was also unusual in the patient who did not respond to the association of plasma exchanges and antiviral agents and was only slightly improved by steroids and cyclophosphamide. COMMENTS. HBV-related PAN is considered to be an immune complex disorder. In the present case report granuloma were present as observed in Churg Strauss syndrome or Wegener's granulomatosis which are the consequence of other pathogenetic mechanisms as anticytoplasmic neutrophil antibodies (ANCA). This case reports underlines the heterogeneity of the PAN group of vasculitis and the probable role for various pathogenetic mechanisms.