Pathology of noncirrhotic portal hypertension: clinicopathologic study in pediatric patients.

From 1995-2002, 14 patients with predominantly prehepatic, noncirrhotic portal hypertension were evaluated. At presentation, the eight females and six males had a mean age of 9 years (range 2-18). Seven were admitted with gastrointestinal, mostly esophageal bleeding, three with splenomegaly, three with hepato-pulmonary syndrome, and one with hyperammonemia. Imaging studies showed portal vein obstruction in six patients and non-obstructed but frequently anomalous vascular patterns, including hypoplasia of the portal vein, in the remaining eight patients. At the onset, liver function was marginally abnormal in all patients, but thrombocytopenia of approximately 100 x 10(9)/L was consistently observed, probably reflecting chronic mild consumption coagulopathy and hypersplenism. The most striking and frequent histopathologic finding in 25 liver samples, was the presence of hypoplastic portal triads with collapsed portal vein radicles. In contrast, other triads showed markedly distended and misshapen portal vein radicles and likely lymphatics. These two patterns of collapse and distention presumably reflect areas of impaired versus overloaded intrahepatic portal venous flow. Some of the biopsies showed variable portal/sinusoidal fibrosis. Four patients (two with intestinal bleeding, two with hepatopulmonary syndrome) required liver transplants and are doing well. Eight patients are doing well clinically after surgical or spontaneous vascular shunting. Two patients with intestinal bleeding and hepato-pulmonary syndrome, respectively) who had congenital dyskeratosis, underwent bone marrow transplantation and died of nonhepatic-related complications. It is possible to suggest prehepatic causes of portal hypertension even in needle biopsies when collapsed portal vein radicles are present in portal triads, but more than one biopsy sample with larger bore bioptomes may be required to see the changes. Conversely, identifying these changes may suggest to the clinicians the need to work-up a patient for portal hypertension.