Noduläre regenerative hyperplasie als nebenwirkung von azathioprin bei morbus Crohn

History: A 48-year-old patient with Crohn's disease was admitted to our hospital with fatigue, icterus, hepatosplenomegaly and ascites. Investigartios: The whole blood count revealed a pancytopenia, hyperbilirubinemia and slightly elevated transaminases. Examination of the liver histology showed areas of enlarged hyperplastic hepatocytes adjacent to areas of atrophic hepatocytes and dilated sinusoids. Diagnosis, treatment and course: Pancytopenia was most likely azathioprine-related. Analysis of the liver histology was highly suggestive of an azathioprine-related, nodular regenerative hyperplasia (NRH). After discontinuation of azathioprine the patient's condition improved substantially. Conclusions: NRH is a rare but potentially serious complication of azathioprine therapy. Other causes include various rheumatological, vascular and myeloproliferative diseases. When azathioprine is precribed it must be borne in mind that it can cause NRH as a potential adverse effect, and liver enzymes should be measured at regular follow-up examinations.