marginal zone b - cell malignant lymphoma is a low - grade malignant non - hodgkin 's lymphoma that develops in mucosa - associated lymphoid tissue ( malt ) . this disease frequently develops in the stomach and also occurs in the salivary gland , thyroid , and lung . most cases are diffuse large b - cell lymphoma , and the incidence of hepatic malt lymphoma is low among cases of primary hepatic malignant lymphoma [ 2 , 3 , 4 , 5 ] . here , we describe a rare case in which a lesion was initially thought to be a single tumor but was ultimately diagnosed as 2 contiguous tumors ( malt lymphoma and hemangioma ) using contrast - enhanced ultrasonography ( ceus ) with sonazoid ( daiichi sankyo , tokyo , japan ) . the patient was a 60-year - old female in whom a tumor of 15 mm in diameter was detected in the couinaud 's segment ( s6 ) of the liver on the grayscale us in a medical examination . she had no subjective symptoms , relevant medical or family history , and did not drink alcohol . physical findings on admission were : blood pressure 136/80 mm hg , pulse rate 80/min , and body temperature 36.4c . blood tests on admission showed hb 10.4 g / dl ( normal 14.017.0 g / dl ) , suggesting a mild anemia . tumor markers were normal , tests for hepatitis b virus ( hbv ) and hepatitis c virus ( hcv ) were negative , and there were no other abnormal findings . grayscale us showed a tumor with a snowman - like appearance and a relatively clear boundary in the s6 of the liver , with hypo- and hyperechoic areas in the lateral and medial parts of the lesion , respectively ( fig . the tumor had a pale , low - density area on unenhanced ct , and prolonged enhancement in the equilibrium phases ( fig . , the whole lesion gave a low - intensity signal on t1-weighted imaging , but isointensity in the lateral part and high intensity in the medial part were seen on t2-weighted imaging . similarly , the lateral part showed high intensity and the medial part had a higher intensity on heavy t2-weighted imaging ( fig . the lateral part was enhanced in the arterial phase , and enhancement persisted in the portal phase . in contrast , the medial part was gradually enhanced in the arterial phase , compared to the portal phase . ceus was performed using an aplio xg ( toshiba medical systems , tokyo , japan ) with a convex probe ( pvt-375bt , 3.75 mhz frequency ) . the mechanical index for the acoustic output was set to 0.2 , and a single focus point was set at the lower margin of the lesion . sonazoid ( 0.5 ml ) was injected into the left cubital vein followed by a flushing with 10 ml of normal saline . the lateral hypoechoic region was homogenously hyperenhanced in the vascular phase ( 040 s ) early after injection , and the contrast medium was washed out after about 30 s. the medial hyperechoic region was gradually stained from the margin toward the central region ( fig . the tumor showed a defect in both hypo- and hyperechoic regions in the post - vascular phase ( after 15 min ) . similar findings were observed after a second intravenous injection of 0.5 ml of sonazoid using defect reperfusion imaging   in the postvascular phase . liver hemangioma was suspected for the medial part of the lesion based on the typical contrast findings on mri and ceus . in the lateral part , the contrast medium was washed out in the vascular phase on ceus early after the intravenous injection of sonazoid . furthermore , the lateral part showed a defect in the postvascular phase , and this defect led to the suspicion of a malignant tumor , including hepatocellular carcinoma ( hcc ) . thus , surgical resection was performed . in a macroscopic examination of the resected specimen , the medial part was whitish and the lateral part was yellowish - white . on hematoxylin and eosin ( he ) staining , the medial part comprised blood vessels formed by a single layer of flattened endothelial cells and an interstitium formed by thin connective tissue , with the vascular lumen filled with blood . based on these findings , the medial part of the tumor was diagnosed as hemangioma . in the lateral part , lymphocyte infiltration in a dense arrangement was observed on he staining , and most lymphocytes contained a moderately sized nucleus , but some cells contained a large nucleus and noticeable nucleolus ( fig . similar findings were present in the germinal center , with atypical lymphocytes invading the germinal center . based on these findings , the lateral part of the tumor was diagnosed as marginal zone b - cell lymphoma . isaacson and wright   first proposed the name of malt lymphoma for extranodal malignant lymphoma of marginal zone b - cell origin in 1983 . malt lymphoma is a low - grade malignant non - hodgkin 's lymphoma that develops in mucosa - associated lymphoid tissue , and accounts for 78% of all cases . malt lymphoma frequently develops in the stomach , and also occurs in the salivary gland , thyroid , and lung . primary hepatic malignant lymphoma is rare , with most cases being diffuse large b - cell lymphoma and less than 10% being malt lymphoma [ 2 , 3 , 4 , 5 ] . many cases of malt lymphoma are solitary , imaging findings are diverse , and it is difficult to make a definite diagnosis based on imaging alone . exclusion of hcc may not be possible and a definite diagnosis can only be made histopathologically after surgical resection in many cases [ 8 , 9 , 10 ] . in our patient , the lesion was initially considered to be a single tumor , but imaging findings indicated that it had 2 distinct regions . a literature search indicated that 2 cases of simultaneous malt lymphoma and hemangioma in the liver have been reported , with focal nodular hyperplasia also present in 1 of these cases [ 11 , 12 ] . in both previous cases , malt lymphoma and hemangioma were separate , and thus there has been no previous case in which the tumors initially appeared to be a single tumor . in our patient , malt lymphoma and hemangioma were in contact , but each tumor was independent , rather than pathologically continuous , on histopathological examination . concomitant malt lymphoma and hemangioma were considered to have no causal relationship in the 2 previous cases [ 11 , 12 ] . the characteristic imaging findings of hepatic malt lymphoma are nonspecific , but include a relatively hypoechoic mass without a clear hypoechoic margin on grayscale us , hypoenhancement of the tumor in the arterial phase on dynamic ct , and low and high intensities on t1- and t2-weighted images on mri , respectively . in ceus using sono view ( bracco , milan , italy ) in 2 patients with hepatic primary malt lymphoma , foschi et al . found that the lesions were inhomogeneously hyperenhanced in the arterial phase and hypoenhanced in the portal and late phases . these 2 patients were hbv - positive : one was an hbv - inactive carrier , and the other had chronic hbv hepatitis . dynamic ct in both patients showed a slight hyperenhancement in the arterial phase , and hypoenhancement in the portal phases , and hcc was suspected . it was difficult to make a preoperative diagnosis , and the tumor was finally diagnosed histopathologically as hepatic malt lymphoma . the development of a malt lymphoma is thought to involve persistent chronic inflammation , and helicobacter pylori infection is well - known in gastric malt lymphoma . in primary hepatic malt lymphoma , chronic liver disorders such as hbv- or hcv - associated chronic hepatitis , hepatic cirrhosis , and primary biliary cirrhosis are occasionally found in the background liver . our patient was negative for viruses and the background liver was normal , but homogenous hyperenhancement was observed in the vascular phase early after sonazoid injection , and the contrast medium was washed out after about 30 s on ceus . a defect was also noted in the postvascular phase , based on which the possibility of a malignant tumor , including hcc , could not be ruled out . however , the presence of 2 contiguous tumors was indicated by real - time evaluation hemodynamics in the tumor using ceus , which indicates the utility of ceus for a proper diagnosis . tumor penetration by existing blood vessels on dynamic ct and mri is a characteristic finding in hepatic malignant lymphoma [ 8 , 10 ] . however , in our case , no blood vessel penetrating the tumor was evident in any imaging . this feature may not have been visualizable in our case , or the absence of blood vessels penetrating the tumor may differentiate primary hepatic malt lymphoma from other malignant lymphomas . only a few reported cases of primary hepatic malt lymphoma have included ceus findings , and no typical enhancement pattern on ceus has been established . the presence of blood vessels penetrating the tumor is useful for the diagnosis of malignant lymphoma , and ceus evaluation of intratumoral hemodynamics in real time may be more likely to visualize penetrating blood vessels , compared to dynamic ct and mri . it is possible that the absence of this feature differentiates primary hepatic malt lymphoma from other malignant lymphomas . confirmation of this possibility will require further evidence from ceus evaluation of more cases of primary hepatic malt lymphoma . the lesion in our patient was initially considered to be a single tumor , but contiguous hepatic malt lymphoma and hemangioma were actually present . the concomitant occurrence of these tumors is rare , and no cases with 2 tumors in contact have been previously reported . the tumors gave different enhancement patterns on ceus and their presence was confirmed histopathologically , based on which we were able to make the final diagnosis .
primary hepatic marginal zone b - cell malignant lymphoma of mucosa - associated lymphoid tissue ( malt lymphoma ) is extremely rare . 
 we present a case in which a lesion was diagnosed as 2 contiguous tumors ( malt lymphoma and hemangioma ) using contrast - enhanced ultrasonography ( us ) with sonazoid . 
 there has been no previous case of contiguous hepatic malt lymphoma and hemangioma . 
 the present case was a female with no medical history . 
 we detected a snowman - like appearance , which was a tumor of 15 mm in diameter with hypo- and hyper - echogenicities in the lateral and medial parts , respectively , in the couinaud 's segment ( s6 ) of the liver on us . 
 the tumor appeared as a single lesion with a low - density area in the unenhanced phase and prolonged enhancement in the equilibrium phases on dynamic ct . on mri , the whole lesion showed a low - intensity signal on t1-weighted imaging , but isointensity in the lateral part and high intensity in the medial part were seen on t2-weighted imaging . 
 on contrast - enhanced us , the lateral hypoechoic region was homogenously hyperenhanced in the early vascular phase , and the contrast medium was washed out after about 30 s ; in contrast , the medial hyperechoic region was gradually stained from the margin toward the central region . 
 the tumor showed a defect in both hypo- and hyperechoic regions in the postvascular phase . 
 hemangioma was suspected for the medial part based on the typical image findings , but the lateral part was not given a diagnosis . 
 thus , surgical resection was performed . 
 the medial part was a hemangioma , and the lateral part was a malt lymphoma by histopathological findings .