[Dihydralazine-induced hepatitis with bridging necrosis. A clinico-pathologic survey of 20 cases].

A hepatitis with bridging necrosis following dihydralazine therapy has been diagnosed bioptically in 20 cases, preferably in women. The duration of drug intake ranged from 2 weeks to 11 months. A relapse following drug re-exposure occurred in 3 cases, one of them had the fifth relapse within 10 years. Histologic features were centrolobular confluent necrosis with inflammatory infiltration in the adjacent liver parenchyma. The periportal parenchyma showed no or slight alteration. The knowledge of the hepatitis with bridging necrosis is important in order to avoid misdiagnosis as chronic or cirrhotic liver processes. 2 cases had been misdiagnosed as extrahepatic obstruction and were laparotomised. After drug withdrawal the liver damage was reversible and had no tendency to a chronic course even in severe cases.