Electron microscopic findings in non-alcoholic fatty liver disease: is there a difference between hepatosteatosis and steatohepatitis?
OBJECTIVE
Non-alcoholic fatty liver disease has long been accepted as benign; however, recent evidence suggests that the disease may progress to cirrhosis and hepatocellular carcinoma, although the natural course of the disease is still unclear. This study was designed to comparatively evaluate electron microscopic features of non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH).


METHODS
Quantitative and semi-quantitative ultrastructural evaluations were performed on liver biopsies from 23 patients, 10 with NAFL and 13 with NASH.


RESULTS
No statistically significant difference was noted between NAFL and NASH patients in ultrastructural features of hepatocytes including megamitochondria, intramitochondrial crystalline inclusions, mitochondrial matrix granules, foamy cytoplasmic appearance, electron-lucent and glycogen-containing nuclear regions, lipofuscin granules, or an increased frequency of vesicles containing electron-dense material in peribiliary Golgi zone; however, the mitochondrial diameter was significantly higher in the NASH patients. Intercellular distance and microvilli between hepatocytes, collagen and electron-dense material accumulation in the space of Disse, electron-dense material accumulation and microvillus density in bile canaliculi did not differ significantly between the groups.


CONCLUSIONS
Our data show that, although NAFL and NASH can be distinguished by their distinct light microscopic features, ultrastructural characteristics are similar, which suggests that NAFL may also have the potential to progress to fibrosis and cirrhosis like NASH.
Ahishali
Emel
E
Department of Gastroenterohepatology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey. emelahishali@yahoo.com
Demir
Kadir
K
Ahishali
Bulent
B
Akyuz
Filiz
F
Pinarbasi
Binnur
B
Poturoglu
Sule
S
Ibrisim
Duygu
D
Gulluoglu
Mine
M
Ozdil
Sadakat
S
Besisik
Fatih
F
Kaymakoglu
Sabahattin
S
Boztas
Gungor
G
Cakaloglu
Yilmaz
Y
Mungan
Zeynel
Z
Canberk
Yurdagul
Y
Okten
Atilla
A
D000328:Adult; D001706:Biopsy; D003593:Cytoplasm / Q000648:ultrastructure; D005234:Fatty Liver / Q000473:pathology*; D005235:Fatty Liver, Alcoholic / Q000473:pathology; D005260:Female; D006056:Golgi Apparatus / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D008930:Mitochondria, Liver / Q000648:ultrastructure*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity