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Int J Clin Exp Pathol 2012;5(6):512-521

Original Article
Hepatic angiomyolipoma: a series of six cases with emphasis on pathological
radiological correlations and unusual variants diagnosed by core needle biopsy

Abbas Agaimy, Nikolaos Vassos, Roland S Croner, Deike Strobel, Michael Lell

Institute of pathology, Department of surgery, Department of medicine-1, and Department of diagnostic and interventional radiology, University
Hospital, Erlangen, Germany

Received May 13, 2012; Accepted June 29, 2012; Epub July 29, 2012; Published August 15, 2012

Abstract: Hepatic angiomyolipoma is rare and may pose differential diagnostic difficulty, particularly if encountered in core needle biopsy. We
studied 6 cases from 5 males and one female (median age, 48.6 yrs). All presented with non-specific symptoms or an incidentally discovered
tumor mass. Two patients had a remote history of chemotherapy for hematological neoplasms (acute lymphoblastic leukemia and Hodgkin
lymphoma respectively) and another had clear cell renal cell carcinoma and anaplastic pancreatic carcinoma diagnosed at autopsy without
definable syndrome. None of the patients had evidence of the tuberous sclerosis complex or renal or other extrarenal angiomyolipoma. Three
tumors were resected completely and three have been only biopsied and followed up. None of the resected cases recurred at a mean
follow-up of 35 months. Histologically, tumors were classified as classical triphasic (1), lipomatous (2), epithelioid/onocytoid (1), epithelioid
trabecular (1) and myelolipomalike (1). The adjacent liver parenchyma was normal in 3 cases, showed pigment cirrhosis in one case and mild
fatty change in another case. One case had clinically diagnosed but histologically unverified cirrhosis. The initial diagnostic impression/ frozen
section was misleading in 5 of the cases and included vascular lesion, focal fatty change, myelolipoma, hepatocellular tumor and oncocytic
neoplasm. All tumors expressed HMB45 and variably desmin. One epithelioid lesion expressed HMB45 and TFE3, but lacked desmin
expression. In conclusion, hepatic angiomyolipomas are increasingly recognized as incidental findings during surveillance for cirrhosis or
investigations for unrelated conditions. Awareness of their diverse morphological spectrum in liver biopsy is necessary to avoid misdiagnosis
as hepatocellular carcinoma, metastatic melanoma or other malignant neoplasms. (IJCEP1205006)

Keywords: Angiomyolipoma, liver; HMB45, myelolipoma, PEComa, TFE3

Address all correspondence to:
Abbas Agaimy, MD
Pathologisches Institut
Universitätsklinikum Erlangen
Krankenhausstrasse 8-10, 91054
Erlangen, Germany.
Tel: +49-9131-85-22288; Fax: +49-9131-85-24745
E-mail: abbas.agaimy@uk-erlangen.de