Liver lipoma: a case report

Abstract

Liver lipoma is a rare benign mesenchymal tumour without malignant degeneration. Lesions may be asymptomatic, nevertheless they may sometimes cause abdominal pain depending upon the size. Usually liver lipomas are an incidental finding during radiological examinations performed for other reasons, and there is no evidence of familiar genetic cluster or predisposing factors but it seems to have a strong association with impaired lipidic profile. In this report, we describe the case of a 72 year old female with a giant liver lipoma observed during an ultrasound examination. The clinical examination was completed with CT and MRI scans. Features of the lesion such as negative attenuation values on multiphasic CT examination and MRI signal drop-out on T ₂ spectral presaturation with inversion recovery sequences, with no enhancement after administration of contrast medium, are suggestive for this kind of benign neoplasm. The purpose of this report is provide an anthological case of liver lipoma, helping to define the diagnostic features with imaging techniques.

Figure 1.

Abdominal ultrasound shows iso-hyperechoic (a) lesion in the left lobe of the liver and its Doppler analysis (b and c) that shows a peripheral pattern of vascularisation.

Figure 2.

CT examination with contrast medium. (a) TC baseline, (b) arterial phase; (c) portal phase; (d) delayed stage coronal acquisition with axial reconstruction. It could be noted that the lesion has a similar attenuation of fat and does not show significant enhancement in subsequent phases of the study. Please note the presence of a splenic angioma. A region of interest (green ring in the figures), was placed on lesion and it shows the HU attenuation changes in different phases of the CT examination. The HU values do not change significantly in the different phases of acquisition. HU, Hounsfield.

Figure 3.

MRI scans in a patient with liver lipoma. (a) axial T₂ weighted image, (b) axial T₁ weighted image; (c) axial in-phase image; (d) axial out-phase image; (e) axial T₂ SPIR image; (f, g) Gadolinium-enhanced fat-suppressed T₁ weighted MRI scan by using THRIVE sequence, early (f at 25^″ after administration of i.v. contrast medium) and delayed (g at 150^″ after administration of i.v. contrast medium) phases. Please notice how lesion is hyperintense on T₁ and T₂ weighted images, without signal drop-out in the core on out-phase sequences owing to few water protons to cancel out the fat signal on the same voxel. There is only a signal drop-out on out-of-phase sequence at the edge of the lesion because in these periferical voxel there is almost the same concentrations of fat and water protons, which cancel out the fat signal. On T₂ SPIR the lesion has signal suppression while in THRIVE sequences the lesion does not show a significant enhancement confirming the benign assumption. The subtle artefact on anteriorly in the left and right sides is caused by an P-reduction = 2 because the patients was uncooperative and claustrophobic. SPIR, spectral presaturation with inversion recovery; THRIVE, T₁ high resolution isotropic volume excitation.