Interesting Cases from Liver Tumor Board

Jeffrey C. Weinreb, M.D.,FACR Yale University School of Medicine [email protected] Common Liver Diseases

Hemangioma Cyst FNH Focal Fat/Sparing THID

Non-Cirrhotic Cirrhotic

Fibrosis Adenoma RN Metastasis DN HCC Cholangioca Nonalcoholic Fatty Liver Disease (NAFLD)

• Pathology resembles alcohol-induced liver injury • Wide spectrum from simple steatosis, to steatohepatitis (NASH, CASH), advanced fibrosis, cirrhosis, and end-stage liver disease • Frequently associated with obesity, type 2 diabetes, and hyperlipidemia • Usually asymptomatic, but may have fatigue, malaise and sensation of discomfort • Most common cause of abnormal LFTs among adults in USA Diffuse Fatty Liver •Pathology – Triglyceride accumulation within hepatocytes

•CT – Attenuation of liver is at least 10HU less that spleen or <40HU (on non- CE scans) – Intrahepatic vessels may appear hyperattenuating c/w liver

•MR – SI loss on opposed-phase images c/w in-phase images Focal Fat Deposition

• May be round, geographic, or perivascular • Characteristic locations – adjacent to falciform lig or ligamentum venosum, in the porta hepatis, and in the GB fossa. • Absence of mass effect on vessels and other structures • Poorly delineated margins • Contrast enhancement similar to or less than normal liver 45 yo f with abdominal pain and daily alcohol consumption Perivascular Fat Deposition

CT

MR

In-phase Opposed-phase

Radiology 2005;237:159-169 Cirrhosis

––Fibrosis Fibrosis ––Nodular Nodular regenerationregeneration ––Disturbed Disturbed bloodblood flowflow

CT MR Pseudocirrhosis • Clinical – In some patients receiving chemotherapy, a morphologic pattern develops similar to that associated with cirrhosis. – Most common with breast cancer, but occurs with other cancers and lymphoma – May occur with hepatotoxic drugs without liver metastases – may be asymptomatic or may cause portal hypertension from venous compression • Pathology – Findings are suggestive of nodular regenerative hyperplasia which is characterized by the formation of regenerative hepatic nodules with compression and atrophy of parenchyma but without hepatic fibrosis. – There may or may not be foci of residual tumor. – It is thought to be a chemotherapeutic response due to shrinkage of tumor with subsequent scarring and nodular regeneration of uninvolved areas •Imaging – A lobular hepatic contour, segmental volume loss, and enlargement of the caudate lobe. – Findings evolve over 1-3 months AJR 1994; 163:1385-1388 Cavernous Hemangioma

• Clinical – Common; 7-20% of adults; female 5:1 •MRI – Very bright on T2WIs – Enhancing nodules that become more numerous and confluent over time intensity – Follows blood pool on all phases – May not fill in Peliosis Hepatis

• Pathology – Rare benign disorder causing sinusoidal dilatation & presence of multiple blood filled lacunar spaces – Usually a path (not imaging) diagnosis • Clinical – Associated with chronic wasting diseases,steroid medications, sprue, diabetes, vasculitis, hematological disorders – Bacillary peliosis hepatis caused by Bartonella species in HIV-positive patients – Complications: Liver failure/cholestasis/portal hypertension/liver rupture leading to shock Peliosis Hepatis – CT Findings –NECT • Multiple hepatic areas of low attenuation • CT findings differ with size of lesions, presence or absence of thrombus within cavity & presence of hemorrhage –CECT • Larger cavities communicating with sinusoids have same attenuation as blood vessels • Thrombosed cavities will have same appearance as nonenhancing nodules • Arterial phase: Early globular vessel-like enhancement – Multiple small accumulations of contrast, hyperdense in center or periphery of lesion • Portal phase: Centrifugal or centripetal enhancement without mass effect on hepatic vessels • Delayed phase: Late diffuse homogenous hyperattenuation characteristic of phlebectatic type Peliosis Hepatis • MR Findings –T1WI • Hypointense • ↑ Signal due to presence of subacute blood suggestive of hemorrhagic necrosis –T2WI • Hyperintense • Multiple foci of ↑ signal due to presence of subacute blood –Post-C • Lesions usually show contrast-enhancement • Cystic cavity with enhancing rim representing hematoma • Strong contrast-enhancement with "branching" appearance caused by vascular component Focal Nodular Hyperplasia (FNH) • Clinical – Common; 2-5% of adults; female 4:1 – Mostly young women with incidental mass – No malignant potential

•MRI – Looks almost like normal liver on non-c scans – 13% multiple – May be lobulated or have pseudocapsule (no true capsule) – Never bleed, no Ca++ – Rarely contain lipid – Scar hypo on T1 and hyper on T2 – Homogenously intensely enhances on HAP – Homogenously washes out rapidly – Delayed enhancement of scar – Only approx 20% have “classic” features – Persistant hyperintensity on delayed scans with Gd-BOPTA Fibrolamellar Carcinoma (FLC)

• Pathology – Diffuse fibrous stroma comprising fibrolamellar bands of collagen and fibrocytes arranged in a lamellar pattern and in delicate bands between nests of tumor cells • Clinical – Uncommon – Primarily young adult (mean age 28) – Not associated with hepatitis B virus, cirrhosis or metabolic abnormalities – Usually normal serum markers – Better prognosis than classic HCC; 5 year survival is 60% • Imaging Findings – Heterogeneously-enhancing, large, lobulated mass with hypointense central scar and radial septa on T2WI • Size: Vary from 5-20 cm (mean 13 cm) – Compared with FNH, FLC is bigger and more heterogeneous, frequently with calcified (68%) central/eccentric scar & features of malignancy (vessel/biliary obstruction, nodal & lung metastases) Hepatic Masses

FNH FLC Prevalence common rare Blood Products never rare Ca++ rare common Fat unusual never Central Scar common common Late Enhanced Scar common some Homogen Art Phase common never Homogen PV Phase common never Ciliated Hepatic Foregut Cyst

• Pathology – Derives from embryologic foregut – Solitary, unilocular cyst made up of ciliated pseudostratified columnar epithelaium, a subepithelial layer of connective tissue layer, a smooth muscle layer, and an outer fibrous capsule • Clinical – Rare. – Typically appears in 50 yo patients with male predominance – Can show malignant transformation (extremely rare) – Since it is the only cililated cyst that occurs in the liver, FNA is diagnostic • Imaging – Usually located in subcapsular location on the anterior aspect of the liver at the insertion of the falciform ligament (medial seg left lobe) – May calcify Pathology Oncology Research 2002;8(4):278-279 BMC Cancer 2006, 6:244 Radiology 1990;175:475-477