Rethinking alcoholic foamy degeneration of the liver: a study of nine cases highlighting complex pathological findings.

Aims: To reveal clinicopathological characteristics of alcoholic foamy degeneration (AFD)-an uncommon form of alcoholic liver injury.

Methods: Clinicopathological features of AFD (n=9) were examined in comparison to those of severe alcoholic hepatitis (SAH; n=12).

Results: Patients with AFD presented with either biochemical liver dysfunction (n=1) or clinical jaundice (n=8). One case had undergone liver transplantation for alcohol-related cirrhosis and hepatocellular carcinoma 2 years and 3 months before presentation. AFD cases were histologically classified into three groups. The non-jaundiced case had mixed macro- and microvesicular bland steatosis. Seven jaundiced cases showed more complex microscopic features with lobular inflammation, acidophilic bodies, cholestasis and lobular distortion. Hepatocytes were pleomorphic, some extensively enlarged with clear cytoplasm, somewhat resembling ballooning degeneration; however, it was mainly due to accumulated lipid droplets ('pseudoballooning'). The remaining case also had predominant changes of AFD, but a few foci showed classical ballooning hepatocytes and Mallory-Denk bodies, in keeping with mixed AFD and steatohepatitis. When compared with patients with SAH, those with AFD had lower white blood cell and neutrophil counts and higher cholesterol levels (all p<0.001). On imaging, ascites and varices were less common in AFD than in SAH (11% vs 75%, p=0.014; 0% vs 67%, p=0.008, respectively). All seven patients with AFD who successfully abstained from alcohol experienced rapid improvement in liver function.

Conclusions: Microscopic findings of AFD are more complex than currently thought, and some cases may be mistaken for steatohepatitis. AFD may also develop in conjunction with steatohepatitis or following liver transplantation.