Benign Liver Tumors

Abstract

Background: Due to the frequent use of medical imaging including ultrasonography, the incidence of benign liver tumors has increased. There is a large variety of different solid benign liver tumors, of which hemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) are the most frequent. Advanced imaging techniques allow precise diagnosis in most of the patients, which reduces the need for biopsies only to limited cases. Patients with benign liver tumors are mostly asymptomatic and do not need any kind of treatment. Symptoms can be abdominal pain and pressure effects on adjacent structures. The 2 most serious complications are bleeding and malignant transformation.

Summary: This review focuses on hepatic hemangioma (HH), FNH, and HCA, and provides an overview on clinical presentations, surgical and interventional treatment, as well as conservative management. Treatment options for HHs, if indicated, include liver resection, radiofrequency ablation, and transarterial catheter embolization, and should be carefully weighed against possible complications. FNH is the most frequent benign liver tumor without any risk of malignant transformation, and treatment should only be restricted to symptomatic patients. HCA is associated with the use of oral contraceptives or other steroid medications. Unlike other benign liver tumors, HCA may be complicated by malignant transformation. HCAs have been divided into 6 subtypes based on molecular and pathological features with different risk of complication.

Key message: The vast majority of benign liver tumors remain asymptomatic, do not increase in size, and rarely need treatment. Biopsies are usually not needed as accurate diagnosis can be obtained using modern imaging techniques.

Keywords: Benign liver tumors; Focal nodular hyperplasia; Hemangioma; Hepatocellular adenoma.

Fig. 1

A 36-year-old female patient with a giant hepatic hemangioma occupying segments IV–VIII. A CT, axial section showing a lesion 22–23 cm in diameter (bidirectional arrows). B CT, coronal section. C Intraoperative view of the hemangioma pushing the right portal vein anteriorly. D Enucleation seemed not to be possible (the right hepatic vein was close and in some parts within the hemangioma); therefore, an extended right hepatectomy was performed after portal vein embolization. The picture shows the surgical specimen with normal hepatic parenchyma and hemangioma. E Surgical specimen with a view to the right hepatic vein. F Situs after extended right hepatic resection (segments IV–VIII). The hypertrophied segments II and III are shown. There is a small hepatic hemangioma in segment III.

Fig. 2

HE-stained sections show the classic morphology of a cavernous hemangioma with widely dilated vascular channels (1) lined by flattened inconspicuous endothelial cells and fibrous walls (2) and focal organized thrombi (inset).

Fig. 3

A 30-year-old male patient with a focal nodular hyperplasia in liver segment IV. A CT, coronal section, showing focal nodular hyperplasia 7 cm in diameter (bidirectional arrows). B CT, axial section. C The depicted operative specimen indicates atypical liver resection of segment IV with a central scar on the cut surface.

Fig. 4

Focal nodular hyperplasia shows characteristic nodular cirrhosis-like architecture with ductular reaction in fibrous septa (1) and thick-walled abnormal arteries (2). Reticulin with Gomori silver staining demonstrated a retained normal reticulin framework (inset).

Fig. 5

A 32-year-old female patient with hepatic adenoma. A The tumor is 10 cm in diameter (bidirectional arrows) in segments VI and VII, coronal section. B CT, axial section. C, D Surgical specimen of an atypical liver resection of segments VI and VII (C) and of normal hepatic parenchyma and hepatic hemangioma visible on the cut surface (D).

Fig. 6

Hepatocellular adenoma with fatty changes limited to the lesion (1) but absent in normal liver (2). Hemorrhage is a common feature (3). Insets: Higher magnification (left inset) does not show portal tracts but so-called naked arteries (*) and, in comparison to hepatocellular carcinoma, no nuclear atypia or mitotic activity. Reticulin (middle inset) with Gomori silver staining demonstrates a preserved reticulin framework somewhat slightly reduced in the lesion versus the normal liver. In this case, β-catenin staining (right inset) was negative with only membranous and no nuclear reactivity. Brown, cell membrane; blue, nucleus.