26 March 2009 Case of the Week #141


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Case of the Week #141


Clinical History


A 42 year old woman presented with possible hepatic adenomas. A resected segment of liver measured 9 x 6 cm, and showed two additional well circumscribed lesions measuring 2.5 and 2 cm.


Gross images: #1; #2

Micro images: #3; #4; #5


What is your diagnosis?




























Nodules of focal fatty change




Focal fatty change was first described in 1980 (Gastroenterology 1980;78:247). It is rare, and often an incidental finding identified at autopsy or with imaging studies. Lesions may be up to 12 cm, be single or multiple, and may clinically simulate malignancy (Przegl Lek 2006;63:695). Microscopically, they consist of focal lipid deposits with preservation of the hepatic architecture.


The differential diagnosis includes other possible lipid-rich lesions, including angiomyolipoma, coelomic fat ectopia (Arch Pathol Lab Med 1985;109:783)

diffuse steatosis, focal nodular hyperplasia, hepatic adenoma, lipoma and myelolipoma. Fatty change has also been reported in hepatocellular carcinoma (AJR Am J Roentgenol 1988;151:717).


The cause of focal fatty change is unknown, but suggested possibilities include focal tissue hypoxia or local effects of insulin in a case of metastatic insulinoma to the liver (Pathol Int 2008;58:59) .




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