[1654] Nodular Elastosis of the Liver: An Under-Recognized Pseudotumor Associated with Segmental Atrophy

AD Singhi, HR Makhlouf, A Mehrotra, Z Goodman, RA Anders, U Drebber, H Dienes, M Torbenson. Johns Hopkins, Baltimore, MD; AFIP, Washington, DC; AIPL, Washington, DC; University of Cologne, Cologne, Germany

Background: Elastotic nodules within the liver are a rare type of pseudotumor that can be associated with areas of segmental or lobar atrophy. These pseudotumors are under-recognized as a diagnostic entity and can be diagnostic challenges because they can present as mass lesions, can demonstrate a range of histological appearances, and because the associated atrophy may not be evident on imaging studies or gross examination. To better understand the full clinicopathological spectrum of this lesion, cases were collected from 3 academic centers.
Design: 16 cases were identified including resections (3), wedge biopsies (10), and needle biopsies (3). Clinical and histological features were evaluated.
Results: A modest female predominance (12/17, 71%) was seen. Ages at presentation ranged from 14 to 91 years (median 65 years). The most common clinical presentation was right upper quadrant abdominal pain (13/17, 76%). All cases showed evidence of a mass lesion. The majority of lesions were subcapsular (14/17, 82%) and ranged in size from 1.8 to 10.0 cm. Based on size, most cases appeared to involve a segment of the liver and only rarely the entire lobe. A striking feature in all cases was the presence of abnormally thick-walled and often thrombosed vessels, typically at the edge of the lesion. Both arteries and veins were affected. Examination of the histological findings for the entire series of cases suggested a sequences of changes, with early lesions (N=4) composed of collapsed hepatic parenchyma with occasional islands of residual hepatocytes and brisk bile ductular proliferation. These cases showed relatively mild elastosis. Other cases (N=10) showed little or no ductular proliferation but had increased levels of elastosis. Finally, 3 cases were composed almost solely of elastosis with small scattered islands of unremarkable hepatocytes. Biliary cysts were also a common finding (6/17, 35%).
Conclusions: Segmental atrophy of the liver is typically subcapsular and is strongly associated with evidence of vascular injury. The lesion appears to have multiple stages marked initially by parenchymal collapse and ductular proliferation, followed by a stage showing resolution of the ductular reaction and increased levels of elastosis. In its final stage, segmental atrophy can present as essentially a pure elastotic nodule of liver.
Category: Liver & Pancreas

Monday, March 22, 2010 1:00 PM

Poster Session II # 192, Monday Afternoon


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