Benign Liver Lesions

For dedicated examinations of unclear, potentially benign liver lesions and for hepatic staging prior to liver surgery, MRl can be recommended as the method of choice. In case a CT scan has already been performed (e.g. a staging CT scan of the thorax and abdomen), MRI should not be omitted if the intra-hepatic findings have direct influence on the further treatment. MDCT is suitable for all emergency situations, since it allows for easy patient access and is associated with very short acquisition times, so that uncooperative or clinically unstable patients can be easily examined. 

This presentation will cover the classification of non-infective benign liver lesions these may be dys-plastic/neoplastic or non-neoplastic (mainly regenerative). 

Mathieu D, Paret M, Mahfouz AE (1997) Hyperintense benign liver lesions on spin-echo Tl-weighted MR images pathologic correlations. Abdom Imaging 22 410-417... 

As discussed above, solid benign liver lesions are very common. It is therefore of the utmost importance to differentiate these from metastases in cancer patients. Unenhanced US is usually not able reliably to differentiate metastases from other lesions. Conversely, the use of contrast agents achieves this goal in most cases, since all common solid benign liver lesions have characteristic dynamic imaging features on contrast-enhanced US and their diagnosis is thus usually unproblematic. Most of these features are analogous to those on dynamic CT and MR. 

Spamer, C., Brambs, H.-J., Koch, H.K., Gerok, W. Benign circumscribed lesions of the liver diagnosed by ultrasonically guided fine-needle biopsy. J. Clin. Ultrasound 1986 14 83-88... 

Identification of intrahepatic foci Clarification of the benignancy or malignancy of focal liver lesions... 

Cavernous haemangiomas are the most common form of benign liver tumours. They occur in the form of a single lesion in approx. 90% of cases. When using pertechnetate labelling, haemangiomas exhibit a reduced uptake of radioactivity in the early perfusion... 

Hruban RH, Sturm PD, Slebos RJ, et al. Can K-ras codon 12 mutations be used to distinguish benign bile duct proliferations from metastases in the liver A molecular analysis of 101 liver lesions from 93 patients. Am J Pathol. 1997 151 943-949. 

A total of 6% of all abdominal tumors in the pediatric age group occur in the liver, i.e., 30% of all benign abdominal lesions, and 0.5%-2.0% of all malignant abdominal lesions (Suchy 2003). An incidence of... 

Radiological Appearance of Different Focal Liver Lesions 397 Solid Benign Lesions 397 Metastatic Liver Lesions 399 Lesions in the Cirrhotic Liver 400 Other Lesions 401... 

Winterer JT, Kotter E, Ghanem N, Langer M (2006) Detection and characterization of benign focal liver lesions with multislice CT. Eur Radiol 16 2427-2443... 

Table 6.1. Benign non-infectious focal liver lesions. Pathological classification...

This type of lesion is a benign tumor of the liver but does not show as a focal liver lesion, but rather with signs related to bile-duct obstruction. 

Apart from hemangioma, other benign mesenchymal lesions of the liver are relatively rare and do not show pathological features that are of value for a sufficiently specific diagnosis at imaging techniques. Hence histology assessment (either on an adequate biopsy specimen or on the resected lesions) is usually unavoidable. Some mesenchymal lesions are more frequent in children. Specific aspects are described in the pertinent literature, mostly as single case reports due to the limited number of observed cases or, in a few instances, summarized in short reviews. 

Karhunen PJ (1986) Benign hepatic tumor and tumor-like conditions in man. J Clin Pathol 39 183-188 King LJ, Burkill GJC, Scurr ED, et al (2002) MnDPDP enhanced magnetic resonance imaging of focal liver lesions. Clin Radiol 57 1047-1057... 

Molina EG, Schiff ER (1999) Benign solid lesion of the liver. In Schiff ER (ed) Diseases of the liver. Lippincott-Raven, pp 1254-1257... 

Another cause of abnormal liver enhancement can be seen in the arterial phase around highly vascularized liver neoplasms. In the dynamic study, the liver around a hypervascular neoplasm can be significantly hypodense compared to the remainder of the normal parenchyma since the iodinated arterial blood flow is strongly diverted to feed the hypervascular liver lesion. This phenomenon maybe seen around benign or malignant liver tumors, which are essentially dependent on the amount of arterial vascularization of the hepatic neoplasm (Fig. 11.18). The phenomenon is transitory and in the portal venous phase of liver enhancement it returns to iso density. 

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