MITOCHONDRIAL ENLARGEMENT AND CRYSTALLOID MATRIX ARRAYS - DISTINCTIVEFINDING IN CHILDHOOD PORTAL-HYPERTENSION DUE TO CAVERNOUS TRANSFORMATION OF THE PORTAL-VEIN

Elongated, enlarged mitochondria with crystalloid matrix arrays were d iscovered in periportal hepatocytes in 11 of 12 children (age 6 to 15 years) with portal hypertension, minimal alterations on light microsco py, and cavernous transformation of the portal vein. Eleven of the chi ldren were clinically well before onset of symptoms, one was anemic wi th megaloblastic bone marrow, and a second had undergone renal transpl antation. Minimal findings by light microscopy included slight portal fibrosis (six cases), pericentral venular fibrosis (one case), mild, p atchy sinusoidal sclerosis (one case), central venular and sinusoidal dilation (two cases), and mild hepatocellular lipid accumulation (one case). Four were judged normal by routine histologic examination. Subt le depletion of periportal hepatocyte cytoplasm was visible with high- magnification light microscopy. Although similar mitochondria are seen sporadically in hepatocytes in diverse settings, enlarged mitochondri a with crystalloid matrix inclusions have not been previously reported as a uniform feature in children with portal hypertension due to cave rnous transformation of the portal vein and minimal other hepatic alte ration. It is postulated that the mitochondria are adapting in respons e to an abnormal metabolic milieu created by hemodynamic alterations.