DOI: 10.1148/rg.246035188
RadioGraphics 2004;24:1719-1724
© RSNA, 2004
Pediatric Hepatic Hemangioma1
Todd S. Regier, MD and
Faridali G. Ramji, MD
1 From the Department of Radiology, Children’s Hospital, University of Oklahoma Health Sciences Center, Rm 1100B, 940 NE 13th St, Oklahoma City, OK 73104. Received September 2, 2003; revision requested October 28 and received December 12; accepted December 22. Both authors have no financial relationships to disclose. Address correspondence to T.S.R. (e-mail: todd-regier@ouhsc.edu).
Index Terms: Angioma, 761.3194 • Liver neoplasms, in infants and children, 761.3194 • Liver neoplasms, diagnosis, 761.1211, 761.1214, 761.1216, 761.1298
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History
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A 5-month-old male infant with a history of persistent gastroesophageal reflux was admitted to the hospital to undergo a Nissen fundoplication. A previous upper gastrointestinal study had demonstrated gastroesophageal reflux to the hypopharynx but no evidence of malrotation. Other than the reflux, the patient was noted to be healthy.
In the operating room, the patient was examined while under general anesthesia, and an abdominal mass was palpated that had not been noted preoperatively. Intraoperative ultrasonography (US) was performed while the patient remained under anesthesia, demonstrating a mass in the right upper quadrant. Exploratory laparoscopy demonstrated a highly vascular mass of the inferior right hepatic lobe filling the right side of the midabdomen (Fig 1). Biopsy was not performed on the mass due to its vascularity. A clinical work-up that included additional imaging was performed before proceeding with any further surgery. Following completion of the work-up, a laparotomy was performed and the mass was removed.
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Figure 1. Photograph obtained during laparoscopy demonstrates a large abdominal mass that appears to arise from the inferior right hepatic lobe. Extensive superficial vascularity is also seen (arrow).
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The laboratory work-up included liver function tests as well as a complete metabolic profile, all of which were normal, with the exception of an 
-fetoprotein level (39.9 ng/mL; normal level, 0–8.0 ng/mL). The ß–human chorionic gonadotropin level was normal.
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Imaging Findings
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Intraoperative US demonstrated a well-defined, solid mass with moderate echogenicity in the right upper quadrant. The mass contained multiple scattered hyperechoic foci without posterior shadowing (Fig 2a). At Doppler US, the lesion appeared to be hypervascular peripherally (Fig 2b). The mass measured 6.3 x 4.9 x 7.4 cm, was located in the inferior aspect of the right hepatic lobe, and had a large exophytic component. It also caused mass effect on the adjacent right kidney. The remainder of the liver appeared normal.
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Figure 2a. (a) Longitudinal US image demonstrates a large, moderately echogenic solid mass (M) in the right upper quadrant. The mass appears to be contiguous with the right lobe of the liver (L) and causes mass effect (black arrowhead) on the kidney (K). Scattered small, nonshadowing hyperechoic foci (white arrowhead) are also seen but did not prove to represent calcifications. (b) Doppler US image demonstrates increased peripheral flow within the mass (arrowhead), with the central portion demonstrating much less vascularity.
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Figure 2b. (a) Longitudinal US image demonstrates a large, moderately echogenic solid mass (M) in the right upper quadrant. The mass appears to be contiguous with the right lobe of the liver (L) and causes mass effect (black arrowhead) on the kidney (K). Scattered small, nonshadowing hyperechoic foci (white arrowhead) are also seen but did not prove to represent calcifications. (b) Doppler US image demonstrates increased peripheral flow within the mass (arrowhead), with the central portion demonstrating much less vascularity.
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Radiography of the abdomen performed the same day showed a soft-tissue mass in the right midquadrant causing mass effect on the bowel, shifting the ascending colon laterally (Fig 3). Four-phase computed tomography (CT) of the liver was performed 2 days later. Unenhanced CT demonstrated a subtle area of hypoattenuation in segments V and VI of the liver (Fig 4). No calcifications were seen. After intravenous administration of contrast material, the lesion enhanced peripherally but remained low in attenuation centrally (Fig 5a). Delayed CT scans showed gradual washout (and thus apparent decrease) of the peripheral enhancement and an increase in the central attenuation of the mass (Fig 5b). There was mass effect on adjacent structures, including the right kidney. The remainder of the liver and abdomen demonstrated no other abnormalities.
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Figure 3. Anteroposterior radiograph of the abdomen shows a soft-tissue mass in the right side of the midabdomen causing mass effect on the adjacent gas-filled colon (arrowhead), which is displaced laterally. There were no obvious calcifications within the mass, whose opacity is similar to that of the liver.
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Figure 4. Unenhanced CT scan demonstrates a prominent inferior right hepatic lobe and an indistinct mass (M) with subtly decreased attenuation relative to the normal parenchyma anteriorly. This subtle difference was more clearly visualized with liver windowing. No calcifications are seen.
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Figure 5a. (a) Dynamic CT scan obtained immediately after contrast material injection demonstrates a large mass with peripheral enhancement in the inferior right hepatic lobe. The central two-thirds of the mass is relatively hypoattenuating. The mass causes mass effect on the adjacent right kidney. A thin rim of normal liver is seen anteriorly and demonstrates less enhancement than the mass. (b) Delayed CT scan obtained 8 minutes after contrast material injection shows the mass with some washout of the peripheral enhancement and an attenuation that is closer to that of normal liver. The mass demonstrates persistent hypoattenuation centrally.
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Figure 5b. (a) Dynamic CT scan obtained immediately after contrast material injection demonstrates a large mass with peripheral enhancement in the inferior right hepatic lobe. The central two-thirds of the mass is relatively hypoattenuating. The mass causes mass effect on the adjacent right kidney. A thin rim of normal liver is seen anteriorly and demonstrates less enhancement than the mass. (b) Delayed CT scan obtained 8 minutes after contrast material injection shows the mass with some washout of the peripheral enhancement and an attenuation that is closer to that of normal liver. The mass demonstrates persistent hypoattenuation centrally.
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Surgical Findings
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Surgical exploration of the abdomen revealed that the lesion extended from the inferior aspect of the right hepatic lobe. It was noted that the lesion was mostly external to the normal liver parenchyma but did invade the liver for approximately 3 cm. The lesion was situated just lateral to the gallbladder with approximately 2–3 cm of intervening normal liver and was removed without difficulty or significant blood loss. No further abnormalities were noted at surgery.
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Pathologic Evaluation
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The pathologic specimen consisted of a bean-shaped mass weighing 94.7 g and measuring 7.5 x 6.5 x 4.7 cm. At gross examination, the tissue was gray and yellow with multifocal dark red components, the largest of which measured 2.0 x 1.2 x 1.2 cm (Fig 6). Less than 10% of the totally resected specimen consisted of normal liver. Histologic findings were consistent with a hemangioma (Fig 7). Multiple endothelium-lined vascular channels, which were dilated and varied greatly in size, were also seen. A few of these channels were thrombosed, and several were irregular in contour. There was surrounding fibroproliferative tissue and a relative lack of intervening liver parenchyma and bile ducts.
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Figure 6. Photograph shows the sectioned gross specimen of the hepatic hemangioma with minimal normal liver tissue. The whitish central portion corresponds to the region of poor enhancement seen at initial contrast material-enhanced CT (cf Fig 5a).
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Figure 7a. (a) Low-power photomicrograph (original magnification, x10; hematoxylin-eosin stain) demonstrates vascular channels of varying size in the hemangioma. The vascular channels are lined with endothelium but contain no blood cells (B indicates one such channel). Note the surrounding fibroproliferative tissue with scarce liver parenchyma. (b) Low-power photomicrograph (original magnification, x40; hematoxylin-eosin stain) demonstrates a thrombosed vascular channel (B) within the hemangioma.
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Figure 7b. (a) Low-power photomicrograph (original magnification, x10; hematoxylin-eosin stain) demonstrates vascular channels of varying size in the hemangioma. The vascular channels are lined with endothelium but contain no blood cells (B indicates one such channel). Note the surrounding fibroproliferative tissue with scarce liver parenchyma. (b) Low-power photomicrograph (original magnification, x40; hematoxylin-eosin stain) demonstrates a thrombosed vascular channel (B) within the hemangioma.
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Discussion
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Hepatic hemangiomas are uncommon causes of an abdominal mass in neonates and infants (1). The differential diagnosis for a hepatic mass in children includes benign and malignant primary tumors, vascular tumors, metastases, cysts, and abscesses. When hepatic masses are symptomatic, they most commonly manifest as a palpable mass with abdominal distention. Other signs and symptoms may include pain, anorexia, weight loss, fever, jaundice, and congestive heart failure (2).
An important differentiating factor in the evaluation of pediatric hepatic masses is the age of the patient (Table). Hemangioendotheliomas, hepatoblastomas, mesenchymal hamartomas, and metastatic disease from Wilms tumor or neuroblastoma are usually seen in the first 3 years of life, whereas hepatocellular carcinoma, focal nodular hyperplasia, hepatic adenoma, and metastases from lymphoma are more common in older children (2).
Hepatic hemangiomas are an unusual finding in the pediatric population and are more common in older children and adolescents than in neonates and infants (2). Hemangiomas are often solitary lesions but are multiple in 10%–20% of cases (3). They are often discovered incidentally at CT or US performed for other purposes. Hemangiomas are more often seen in the periphery of the liver than centrally (3). They can manifest (as in this case) as a palpable abdominal mass if they grow large enough and may be associated with high-output cardiac failure due to arteriovenous shunts located within the tumor (4).
There are multiple interfaces between the walls of the vascular channels and the intravascular blood (5); thus, the classic US appearance of a hemangioma is that of a strongly echogenic mass, especially hemangiomas measuring less than 3 cm in diameter (6). However, the findings may vary widely, with smaller hemangiomas appearing more homogeneous and larger hemangiomas having a more complex US appearance (7). Larger hemangiomas may contain calcifications, cystic spaces, and areas of fibrosis that give them a heterogeneous US appearance. This heterogeneous appearance at US can been seen in a variety of other causes, including primary benign and malignant tumors as well as metastases.
CT is often used in conjunction with US for the work-up of abdominal and hepatic masses. These masses typically appear at unenhanced CT as an area of well-demarcated hypoattenuation within the liver, often in the periphery of the liver parenchyma. On dynamic scans obtained after intravenous administration of contrast material, there is typically peripheral enhancement of the lesion with central nonenhancement. Delayed CT scans demonstrate washout of the peripheral enhancement with filling in of the central portion of the lesion due to the slower flow of blood through the lesion compared with the surrounding normal liver parenchyma. As a result, the lesion may appear to be isoattenuating relative to the remainder of the liver parenchyma at delayed imaging. It may be possible to overlook a hepatic hemangioma if delayed scans but not dynamic scans are obtained (8). Small hemangiomas may demonstrate central enhancement on initial scans, a finding that may be regarded as analogous to the peripheral enhancement seen in larger lesions (6). Freeny and Marks (9) observed diminished attenuation at unenhanced CT, peripheral contrast enhancement on dynamic scans, and complete isoattenuating filling in of the lesion on delayed scans in just over one-half of cases of hemangiomas. The authors suggest that these three criteria be used to make a specific diagnosis of hemangioma.
Magnetic resonance (MR) imaging is also being used increasingly to image hepatic masses. Hemangiomas usually appear hypointense on T1-weighted images and markedly hyperintense on T2-weighted images, probably because of the slow blood flow through the multiple small vascular channels of the tumor (3). However, regions of inhomogeneity, characterized by areas of hypointensity in an otherwise hyperintense lesion, may be seen if fibrosis is present within the lesion (10). In addition, areas of increased signal intensity relative to the already hyperintense lesion can be seen on T2-weighted MR images if cystic changes or hemorrhage is present (3). These areas of inhomogeneity occur more often in larger hemangiomas. Unfortunately, both metastatic disease and primary tumors may also have this appearance. Contrast-enhanced MR imaging can be helpful in distinguishing between hemangiomas and malignancies when the signal intensity of the lesion is indeterminate or heterogeneous, or in a patient with a known primary tumor with potential for cystic or necrotic metastases (11).
After intravenous administration of contrast material, an enhancement pattern similar to that seen at CT is demonstrated (2), with early peripheral enhancement and delayed central filling. However, even after contrast material administration, there are some limitations with MR imaging, which cannot reliably help distinguish hemangiomas from some other lesions, such as hypervascular malignancies (12).
Scintigraphy is yet another modality that can be used to evaluate for hepatic hemangiomas. Studies performed with technetium-99m sulfur colloid or iminodiacetic acid derivatives show a nonspecific defect in the region of the lesion; however, these studies have low sensitivity and specificity (7). Hepatic hemangiomas are often imaged with use of technetium-99m–labeled red blood cells. An increased ratio between the radiotracer activity in the hemangioma and that in the surrounding liver at imaging performed at 1–2 hours is diagnostic for hemangiomas; however, these studies may demonstrate activity in the hemangioma that is equal to or less than that in the surrounding parenchyma on delayed scans (13). Hypervascular metastases will accumulate radiotracer early, whereas hemangiomas will do so later (7). In the event of central necrosis or fibrosis, photopenic areas may be seen, but the remainder of the hemangioma should show persistent uptake on delayed scans (14).
Diagnosis of a hepatic hemangioma may be difficult if the lesion does not have the classic appearance of hemangioma at the various modalities as discussed earlier. Multiple factors can cause an altered appearance, including calcifications, fibrosis, and thrombosis of portions of the tumor and cystic or necrotic areas within the tumor. Lesion size is another consideration, with larger lesions being more heterogeneous. If the diagnosis is uncertain due to unusual imaging characteristics, history of a known malignancy, or concern for metastatic disease, more definitive information is needed and can be obtained with further imaging with different modalities or with open biopsy.
Histologic evaluation remains the standard of diagnosis; however, at fine-needle biopsy, it is possible that only endothelial cells and red blood cells are obtained, leading to a nondiagnostic sample.
In a patient under the age of 6 months, the most common hepatic mass is a hemangioendothelioma (2), which can appear similar to a hemangioma at CT and MR imaging. In addition to histopathologic analysis, there are several factors that can help distinguish between a hemangioendothelioma and a hemangioma, including patient age at presentation, lesion size and location, number of lesions, signs and symptoms, and lesion appearance at US (Table) (2,3,7).
At pathologic analysis, hemangiomas demonstrate multiple dilated venous channels of varying size with surrounding fibroproliferative tissue. Hemangioendotheliomas have been characterized as either type 1 or 2. Type 1 hemangioendotheliomas have irregularly dilated vascular spaces lined with plump endothelial cells surrounded by a fibromyxomatous stroma (15). Bile ducts may be mixed between the vascular channels, and areas of extramedullary hematopoiesis may be present in the stroma or within the lumen (15). Type 2 hemangioendotheliomas contain poorly formed and anastamosing vascular channels with papillae lined with atypical endothelial cells (15).
Because many hemangiomas are found incidentally and in the absence of clinical signs or symptoms, they can often be safely followed up with US. In our case, the patient was asymptomatic but had an elevated -fetoprotein level. This finding can be seen in both hepatic and nonhepatic malignancies, as well as in children with nonmalignant liver dysfunction such as hepatitis and biliary atresia (16). After taking into account the size of the lesion, its heterogeneous appearance at US, and the patient’s elevated -fetoprotein level, we decided to have the lesion surgically removed rather than simply monitor its course.
The patient did well postoperatively. After surgery, the patient’s liver enzyme levels initially increased and then returned to normal range over a period of a few days. These levels remain in normal range, and no sign of liver dysfunction has been noted. Follow-up US of the liver demonstrated postoperative changes but was otherwise normal. The patient continued to experience reflux and eventually underwent a Nissen fundoplication.
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Conclusions
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Hepatic hemangiomas are benign tumors that rarely occur in infants, and when they do they are usually found incidentally. Hemangiomas have a classic appearance at MR imaging, CT, US, and scintigraphy; unfortunately, these classic findings are seen only at times. Multiple factors including lesion size and the presence of thrombosis, fibrosis, calcifications, and cystic spaces can cause an irregular appearance and thus increase the difficulty of distinguishing a hemangioma from some other lesion. This complication of diagnosing hemangiomas is obviously important, since most hemangiomas are asymptomatic and may be followed up, whereas other lesions such as primary and metastatic lesions may require further therapy.
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References
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- Dehner L, Ishak K. Vascular tumors of the liver in infants and children. Arch Pathol 1971; 92:101-109.[Medline]
- Siegel M. Pediatric liver imaging. Semin Liver Dis 2001; 21:251-269.[CrossRef][Medline]
- Powers C, Ros P, Stoupis C, Johnson W, Segel K. Primary liver neoplasms: MR imaging with pathologic correlation. RadioGraphics 1994; 14:459-482.[Abstract]
- Prokurat A, Kluge P, Chrupek M, Kosciesza A, Rajszys P. Hemangioma of the liver in children: proliferating vascular tumor or congenital vascular malformation? Med Pediatr Oncol 2002; 39:524-529.[CrossRef][Medline]
- McArdle C. Ultrasonic appearances of a hepatic hemangioma. J Clin Ultrasound 1978; 6:124.[Medline]
- Itai Y, Ohtomo K, Araki T, Furui S, Iio M, Atomi Y. Computed tomography and sonography of cavernous hemangioma of the liver. AJR Am J Roentgenol 1983; 141:315-320.[Abstract/Free Full Text]
- Ros PR, Li KC. Benign liver tumors. Curr Probl Diagn Radiol 1989; 18:125-155.[CrossRef][Medline]
- Bree R, Schwab R, Neiman H. Solitary echogenic spot in the liver: is it diagnostic of a hemangioma? AJR Am J Roentgenol 1983; 140:41-45.[Free Full Text]
- Freeny P, Marks W. Hepatic hemangioma: dynamic bolus CT. AJR Am J Roentgenol 1986; 147:711-719.[Abstract/Free Full Text]
- Ros P, Lubbers P, Olmsted W, Morillo G. Hemangioma of the liver: heterogeneous appearance on T2-weighted images. AJR Am J Roentgenol 1987; 149:1167-1170.[Abstract/Free Full Text]
- Bennett G, Petersein A, Mayo-Smith W, Hahn P, Schima W, Sinai S. Addition of gadolinium chelates to heavily T2-weighted MR imaging: limited role in differentiating hepatic hemangiomas from metastases. AJR Am J Roentgenol 2000; 174:477-485.[Abstract/Free Full Text]
- Li K, Glazer G, Quint L, et al. Distinction of hepatic cavernous hemangioma from hepatic metastases with MR imaging. Radiology 1988; 169:409-415.[Abstract/Free Full Text]
- Moinuddin M, Allison J, Montgomery J, Rockett J, McMurray J. Scintigraphic diagnosis of hepatic hemangioma: its role in the management of hepatic mass lesions. AJR Am J Roentgenol 1985; 145:223-228.[Abstract/Free Full Text]
- Bree R, Schwab R, Glazer G, Fink-Bennett D. The varied appearances of hepatic cavernous hemangiomas with sonography, computed tomography, magnetic resonance imaging and scintigraphy. RadioGraphics 1987; 7:1153-1175.[Abstract]
- Dehner L. Liver, gallbladder, and extrahepatic biliary tract. Pediatric surgical pathology. 2nd ed. Baltimore, Md: Williams & Wilkins, 1987; 433-523.
- Kashyap R, Jain A, Nalesnik M, et al. Clinical significance of elevated alpha-fetoprotein in adults and children. Dig Dis Sci 2001; 46:1709-1713.[CrossRef][Medline]
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History
Imaging Findings
