Pictorial review of hepatic echinococcosis: Ultrasound imaging and differential diagnosis

Table 4 Differential diagnosis of solid hepatic echinococcosis

Entities	Medical history	Sonographic features	Laboratory examination
HCE (HCE4, HCE5)	History of travel to endemic areas	B-mode: The mass shows the “cerebral gyri” sign with intermittent hyperechoic and hypoechoic signals, as well as scattered, annular, and “eggshell-like” calcification. CEUS: Most of the masses show no enhancement in both their interior and margins	Heat-resistant B antigen, with 20%-58% negative results
HAE	History of travel to endemic areas	B-mode: An ill-defined, heterogeneously echoic mass with diffuse, scattered, or focal calcification and possible liquefactive necrosis. CEUS: In the AP, an enhanced and irregular “rim-like” peripheral band can be observed surrounding the lesion, with no obvious internal enhancement, presenting as a “black hole” sign	Specific antigens such as Em2 or Em18, with 90% positive results
Hepatic paragonimiasis	History of eating undercooked shrimp and crabs	B-mode: An irregularly shaped and heterogeneous lesion with an internal appearance resembling “tunnel-like” echoes. CEUS: The lesion shows uneven enhancement in the AP, with non-enhancing reticular and “tunnel-like” areas internally	Stool examination
Liver abscess	History of diabetes, high fever, pain upon percussion in the liver area	B-mode: Thick-walled septated cystic lesions with areas of liquefied necrosis, including some with an air-fluid level within the cysts. CEUS: The mature liver abscess shows hyper-enhancement of the cystic wall and internal septa in the AP, with multiple patches of non-enhancing liquefied necrotic areas, resembling a “honeycomb-like” pattern	CBC, CRP
HCC	History of underlying liver disease associated with hepatitis and alcohol intake	B-mode: Swelling growth with a “hump” sign. CEUS: The typical HCC shows uniform hyper-enhancement in the AP and begins to wash out with slightly lower enhancement in the LP	AFP, AT
ICC	History of hepatolithiasis	B-mode: An ill-defined lesion, often accompanied by biliary duct dilation and early metastasis to hepatic hilar lymph nodes. CEUS: The mass-forming ICC shows irregular “rim-like” peripheral enhancement in the AP, washout in the PVP, and significant hypo-enhancement in the LP	CA 19-9
Liver metastases	Mainly arising from primary cancers of the lung, gastrointestinal tract, pancreas, and breast	B-mode: Multiple hypoechoic or hyperechoic masses within the liver. CEUS: The mass shows a thick “rim-like” hyper-enhancement in the early AP, washout in the late AP, and significant hypo-enhancement in the PVP and LP, presenting as a “bull's eye” sign	CEA, CA 72-4, CA 15-3, CA 125, CA 19-9
HBCA	Mainly in middle-aged women	B-mode: The cystic-solid mass with mixed echogenicity has a “multi-room-like” structure, often with solid wall nodules growing towards the cavity. CEUS: The enhancement of the lesion can be observed in “multilocular-like” septa, walls, and wall nodules in the AP	-
HCA	Women who take oral contraceptives	B-mode: A well-defined, homogeneous mass with clear borders. CEUS: The mass shows overall high enhancement in the AP and primarily iso-enhancement in the PVP and LP	-
FNH	Mainly in young and middle-aged women	B-mode: Central scar with a radial distribution within the mass. CEUS: The typical FNH presents as centrifugal enhancement in a “spoke-wheel” or “firework-like” pattern from the center to the periphery in the AP, with slight hyper-enhancement in the PVP and LP	-
HSH	-	B-mode: A “sieve pore-like” hyperechoic mass. CEUS: The typical HSH shows discontinuous, nodular peripheral enhancement in the AP, with progressive partial or complete centripetal fill-in in the PVP and slight hyper-enhancement in the LP. A non-enhancing area can be observed within the lesion	-
Hepatoblastoma	Predominantly in children under five years of age	B-mode: A slightly lobulated, heterogeneously echogenic mass with visible liquefied necrotic areas. CEUS: The mass shows hyper-enhancement in the AP and begins to wash out in the PVP, with no enhancement in the liquefied necrotic zone	AFP

HCE: Hepatic cystic echinococcosis; CEUS: Contrast-enhanced ultrasound; HAE: Hepatic alveolar echinococcosis; AP: Arterial phase; CBC: Complete blood cell count; CRP: C-reactive protein; HCC: Hepatocellular carcinoma; LP: Late phase; AFP: Alpha fetoprotein; AT: Abnormal thrombin; ICC: Intrahepatic cholangiocarcinoma; PVP: Portal venous phase; CA: Carbohydrate antigen; CEA: Carcinoembryonic antigen; HBCA: Hepatic biliary cystadenoma; HCA: Hepatocellular adenoma; FNH: Focal nodular hyperplasia; HSH: Hepatic sclerosing hemangioma.