Case of the Month: November 2018 Mirek Mychajlowycz, PGY2 Diagnostic Radiology McMaster University

Case Presentation 65M seen in ER Chief complaint: RUQ fullness and pain with 4.5kg weight loss PMHx: non-contributory Physical exam: Liver edge palpable 6cm below inferior costal margin and tender Negative Murphy’s sign, remainder of exam normal Labs: WBC, LFTs normal Imaging: CT abdomen pelvis C+, followed by MR C+ (Gd)

CT Findings Portal venous phase: Large right lobe posterior segment liver mass Discontinuous, nodular, peripheral enhancement Enhancement follows aortic attenuation (blood pool) Central low attenuation in keeping with a fibrous scar

CT Findings Delayed phase: Progressive centripetal enhancement Mass is iso-/hyper-attenuating to liver parenchyma *Central scar

MR Findings T1: Mass hypointense to liver T1 C+ (Gadolinium): Peripheral nodular discontinuous enhancement that progresses inward Mass replaced right hepatic lobe IVC compressed but patent, left portal vein obliterated T1 T1 C+ T1 C+ T1 C+

MR Findings T2: Mass hyperintense to liver parenchyma T2 Coronal MR Findings T2: Mass hyperintense to liver parenchyma Lower intensity than a hepatic cyst *Relatively hyperintense central scar T2 Axial

Giant Hepatic Cavernous Hemangiomas (GHCHs) AKA slow flow venous malformation (ISSVA) Atypical subset of hepatic hemangioma (most common benign liver tumor) Epidemiology: 5:1 female-to-male distribution Age at diagnosis 30-50 yrs Thought to be congenital but etiology is unknown Considered giant when >5 cm Composed of a tangle of endothelial-lined blood- filled cavities fed by the hepatic artery H&E stain: varying sized channels with RBCs within surrounded by fibrous connective tissue

GHCH Differential Diagnosis Depending on the imaging modality and patient history, the differential may include: Hepatic metastases – hypervascular mets (eg. thyroid cancer and renal cell carcinoma) are often multiple, show marked early enhancement and do not retain contrast on delayed images Hepatocellular carcinoma – enhances vividly in the arterial phase then washes out in the PV phase Hepatic cyst – generally <1 cm, may be equivocal on CT and can be resolved on targeted ultrasound exam

GHCH Differential Diagnosis Continued Hepatic abscess Hepatic adenoma Intrahepatic cholangiocarcinoma Focal nodular hyperplasia

Clinical Presentation of GHCH Most are asymptomatic Mass effect, hemorrhage and thrombosis may cause abdominal fullness and pain due to liver capsule stretching Mass effect on biliary tree or vascular structures may cause variable clinical presentations (ex. jaundice, ischemia) History of steroid use, pregnancy, ovarian stimulation (clomiphene) and/or hormone replacement therapy may accelerate development

GHCH Associations Hepatic hemangiomatosis Klippel-Trenaunay-Weber disease Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu disease) Von Hippel-Lindau disease

Further Imaging Preoperative angiography for embolization: Characteristic “snowy tree” or cotton wool appearance Almost pathognomonic of a hemangioma

Further Imaging * Ultrasound Well-defined hyperechoic lesion 10% hypoechoic on background of hepatic steatosis *Central anechoic scar Colour doppler: peripheral feeding vessels Contrast-enhanced: Arterial – peripheral nodular discontinuous enhancement PV/delayed - progressive filling until hyperechoic to liver *

Complications of GHCH Increased risk of complications compared to typical hemangiomas Inflammatory changes Intralesional hemorrhage Intraperitoneal hemorrhage Volvulus of a pedunculated lesion Kasabach-Merrit syndrome: consumptive thrombocytopenia resulting in intravascular coagulation, clotting, and fibrinolysis within the hemangioma and may spread systemically; 20-30% mortality

GHCH Management Generally conservative unless symptomatic No known risk of hepatic malignancy NEVER biopsy due to increased risk of hemorrhage Non-surgical: Arterial embolization +/- radiation and interferon therapy Surgical: Enucleation or liver resection

References Bajenaru N, Balaban V, Savulescu F, Campeanu I, & Patrascu T. (2015). Hepatic hemangioma review. J Med Life, 8: 4-11 Bell, D & Weekrakkody, Y. (2018). Hepatic hemangioma. Radiopedia. Retrieved November 1, 2018 from https://radiopaedia.org/articles/hepatic-haemangioma- 3#image_list_item_1884114 Knipe, H & Yang, N. (2018). Giant hepatic venous malformations. Radiopedia. Retrieved November 1, 2018 from https://radiopaedia.org/articles/giant-hepatic-venous- malformation Machado M et al. (2006). Liver hemangiomas: Ultrasound and clinical features. Radiol Bras, 29(6): 441-446 Madoff, S. (2009). Case 77: Giant hepatic cavernous hemangioma. UR Medicine Imaging. Retrieved November 1, 2018 from http://urmc- mirc2.urmc.rochester.edu/storage/ss1/docs/20090520081002118/MIRCdocument.xml Prasanna P, Fredericks S, Winn S, & Christman R. (2010). Giant cavernous hemangioma. RadioGraphics, 30(4): 1139-1144