Fig. 1: Histologic features useful in the diagnosis of obliterative portal venopathy.
a A portal tract with diminished portal vein and increase in portal stromal fibrous tissue. Note that a markedly dilated thin-walled vessel is present in the periportal area directly abutting the liver parenchyma. b A fibrotic portal tract with a nodular contour and complete obliteration of portal vein. Note that several minute, slit-like vascular channels and a scant chronic inflammatory infiltrate are present within the portal tract. c Two closely approximated portal tracts with nodular contours and diminished portal veins, suggestive of possible parenchymal atrophy. d A rounded portal tract expanded by dense stromal fibrosis (Masson trichrome). Note that a normal, centrally located portal vein is absent. A venous structure with a caliber comparable to the portal arterioles is present at the periphery of the portal tract. e A nodular, large-sized portal tract with stromal fibrosis and muscularized portal venous wall (Masson trichrome). A few thin-walled vessels were present. Only a portion of this portal tract was sampled in the biopsy. f Nodular regenerative hyperplasia with central widened hepatocyte plates surrounded by peripheral atrophic hepatocyte plates and compressed sinusoidal spaces (reticulin stain).
