Imaging of Atypical Hemangiomas of the Liver with Pathologic Correlation

Abstract

Compared with the imaging features of typical hepatic hemangiomas, the imaging features of atypical hepatic hemangiomas have not been well studied or well described. Knowledge of the entire spectrum of atypical hepatic hemangiomas is important and can help one avoid most diagnostic errors. A frequent type of atypical hepatic hemangioma is a lesion with an echoic border at ultrasonography. Less frequent types are large, heterogeneous hemangiomas; rapidly filling hemangiomas; calcified hemangiomas; hyalinized hemangiomas; cystic or multilocular hemangiomas; hemangiomas with fluid-fluid levels; and pedunculated hemangiomas. Adjacent abnormalities consist of arterial-portal venous shunt, capsular retraction, and surrounding nodular hyperplasia; hemangiomas can also develop in cases of fatty liver infiltration. Associated lesions include multiple hemangiomas, hemangiomatosis, focal nodular hyperplasia, and angiosarcoma. Types of atypical evolution are hemangiomas enlarging over time and hemangiomas appearing during pregnancy. Complications consist of inflammation, Kasabach-Merritt syndrome, intratumoral hemorrhage, hemoperitoneum, volvulus, and compression of adjacent structures. In some cases, such as large heterogeneous hemangiomas, calcified hemangiomas, pedunculated hemangiomas, or hemangiomas developing in diffuse fatty liver, a specific diagnosis can be established with imaging, especially magnetic resonance imaging. However, in other atypical cases, the diagnosis will remain uncertain at imaging, and these cases will require histopathologic examination.

Liver haemangioma: common and uncommon findings and how to improve the differential diagnosis

“…Being devoid of malignant potential, they are, in general, fortuitously discovered during any abdominal imaging work-up, mostly being discovered between the fourth and fifth decades of life [5][6][7]. They are multiple in more than 50% of cases and show a clear female predilection (ratio of 2-5:1).…”

“…Their size usually remains stable and can vary from a few millimetres to more than 20 cm, a feature that has been used for its classification into small (<15 mm), medium (15-50 mm) and large haemangiomas (>50 mm) [6]. Large haemangiomas may give rise to complications in 4.5% to 19.7% of cases, consisting of bleeding, compressive effect on adjacent structures such as the bowel and torsion if pedunculated [6,7,9,10]. …”

“…This classical presentation is diagnostic with a high level of confidence [5,6]. Late intra-tumoural accumulation of contrast can be explained by the slow flowing blood within its vascular channels determining iso-/hyperdensity and absence of noticeable washout on the latter phases of the dynamic study [5,7,12,13]. However, delayed homogeneity due to complete contrast filling of the tumour should not be regularly expected, especially for large tumours, and, thus, should not be used as mandatory diagnostic criteria.…”

Neural Network Ensemble Based CAD System for Focal Liver Lesions from B-Mode Ultrasound

“…Typical FLLs can be easily diagnosed by radiologist from their classic sonographic appearances, but differential diagnosis in the presence of atypical FLLs is considered to be a daunting challenge faced by the radiologists during routine practice [7,9,11,[14][15][16][17].…”

“…Typical Cyst appears as round, anechoic lesion with posterior acoustic enhancement and well defined thin imperceptible wall [5,9,10,21]. HEM is the most common primary benign FLL [1,7,9,17,22]. Almost 70 % of all the HEM cases encountered in routine practice are typical HEMs.…”