A pictorial review of benign hepatocellular nodular lesions: comprehensive radiological assessment incorporating the concept of anomalous portal tract syndrome

Abstract

Background/purpose Although the pathological categorization system advocated by the International Working Party (IWP) on Terminology has been helpful in categorizing benign hepatocellular lesions, the diverse clinicopathological features of the lesions still cause confusion of diagnosis in clinical settings. Recently, an integrated disease concept termed ''anomalous portal tract syndrome'' (APTS) has been proposed as a congenital anomaly of the portal tract, being a single unifying etiological factor underlying the disorder. In this article, we discuss the radiological features of benign nodular hepatocellular lesions incorporated in the concept of APTS. Methods We systematically reviewed the literature on benign hepatocellular lesions based on the concept of APTS, as well as standard IWP terminology. For this pictorial review, we selected six representative cases and assessed the radiological features of the cases based on the concept of APTS. Results The comprehensive assessment based on APTS enabled the systematic categorization of benign hepatocellular lesions, including nodular regenerative hyperplasia, large regenerative nodules, partial nodular transformation, focal nodular hyperplasia, and hepatocellular adenoma, and was helpful in understanding the overlapping features of these lesions. Conclusions Although the disease concept of APTS is still evolving, it is nonetheless helpful in comprehensively understanding the clinicopathological and radiological features of various benign hepatocellular lesions.

Histological and Immunohistochemical Revision of Hepatocellular Adenomas: A Learning Experience

“…Focal liver cell lesions including HCA, HCC, focal nodular hyperplasia, and nodular regenerative hyperplasia have been reported in association with congenital absence of the portal vein, also known as congenital extrahepatic portosystemic shunt or Abernethy malformation [5–8, 25–27]. It has been suggested that the decreased venous blood flow combined with an increased arterial blood flow could result in abnormal perfusion of the liver and to uneven vascular perfusion of the liver giving rise to a hyperplastic response, and to a spectrum of nodular lesion including HCA [5, 28]. A study on the complications of congenital portosystemic shunts in children has shown the presence of 13 tumors in 17 patients (76%), 4 corresponding to HCA, one transformed in HCC [26].…”

“…In the man, no liver parenchyma outside the lesion was available, but in the woman we observed similar anomalies in the portal tracts of the normal parenchyma than those described and observed in case of congenital absence of the portal vein. The concept of anomalous portal tract syndrome [28] has been proposed as a single unifying etiological factor underlying the development of the different types of liver nodules in the context of vascular abnormalities, although for HCA the mechanisms are still poorly understood.…”

Hepatocellular nodules resulting from congenital extrahepatic portosystemic shunts can differentiate into potentially malignant hepatocellular adenomas

“…Hepatocellular nodules resulting from CEPS occur as a result of abnormal portal blood flow and are mostly cases of benign focal nodular hyperplasia (FNH) [3][4][5][6][7] that can be multifocal or massive. Although it is believed that the malignant transformation of hepatic nodules does not occur, hepatocellular adenomas (HCA) [8][9][10][11][12][13], hepatoblastomas (HB) [14][15][16][17], and hepatocellular carcinomas (HCC) [18][19][20][21][22][23][24][25] have been described in CEPS patients. If hepatocellular nodules resulting from CEPS are potentially malignant and neoplastic, surgical interventions may be indicated for patients with CEPS and hepatocellular nodules.…”

Pathological Diagnosis of Benign Hepatocellular Nodular Lesions Based on the New World Health Organization Classification

“…Nontypical cases with hepatocellular hemangiomatous lesions can also be interpreted by this concept [21]. Although this concept alone may not be sufficient to explain the etiology of many lesions including IPH and NRH, it is recommended to consider this concept when we encounter various difficult cases [22]. Recently, the original concept (fig.…”