[1565] Histopathologic Features of Extensive Hepatic Vascular Malformations

S Cho, V Paradis, R Pai, P Bioulac-Sage, V Alves, T Souza, H Makhlouf, P Schirmacher, K Evason, L Ferrell. Univ Calif, San Francisco; Hospital Beaujon, Clichy, France; Wash Univ, St Louis; Hospital Pellegrin, Bordeaux, France; Univ Sao Paulo, Sao Paulo, Brazil; Hospital Alianca, Salvador, Brazil; AFIP, Washington, DC; Univ Hospital, Heidelberg, Germany

Background: Hepatic vascular malformations (HVM), often occurring in the setting of hereditary hemorrhagic telangiectasia (HHT, or Osler-Weber-Rendu syndrome) are increasingly recognized by imaging studies. While the clinical manifestations of HHT are well known, the histopathology of HVMs has not been studied extensively. We aim to characterize these rare diagnostically challenging lesions.
Design: Specimens (10) ranged from wedge biopsies (2/10) to partial (1/10) and total hepatectomies (7/10). H&E, elastic, reticulin, CD34, SMA, and D2-40 stains were performed to characterize the vascular types and effects/changes in the background liver.
Results: 7 patients have a clinical diagnosis of HHT; 3 patients lack a definitive diagnosis of HHT. Histologic examination shows a wide spectrum of complex changes. Some cases (4/10) show exclusively venous alterations, while others have arterial changes ranging from isolated arteries (1/10) and focal thick-walled arteries (2/10) to arteriovenous malformation-like areas (3/10). Mild/early changes consist of abnormal portal vessels and central veins with periportal telangiectases, sinusoidal dilation, and periduct fibrosis. The larger abnormal vessels show irregularly thickened walls with an irregular or fragmented elastic lamina and increased smooth muscle, as well as focal recent to organizing thrombi. The periportal telangiectases lack organized elastic fibers but demonstrate increased SMA and patchy CD34 positivity. Moderate/later changes include periportal fibrosis and greater degree of sinusoidal dilation with increased SMA and CD34 staining, with foci resembling cavernous hemangioma. Severe/end-stage changes demonstrate extensive sinusoidal fibrosis with widened hepatic plates often 3-5 cells thick, nodular regenerative hyperplasia or focal nodular hyperplasia-like lesions (7/10), and bile duct alterations, including ectasia, cysts, fistulas, stones, infarcts, and infections. Late stage lesions are also associated with cardiac failure and sepsis.
Conclusions: HVMs of the liver demonstrate changes that likely reflect progression of abnormal vascular flow over time, and recognition of this wide spectrum of pathologic changes should enhance our diagnosis of these problematic lesions.
Category: Liver & Pancreas

Monday, March 22, 2010 1:00 PM

Poster Session II # 190, Monday Afternoon


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