Hepatocellular adenoma: when and how to treat? Update of current evidence

Abstract

Hepatocellular adenoma (HCA) is a rare, benign liver tumor. Discovery of this tumor is usually as an incidental finding, correlated with the use of oral contraceptives, or pregnancy. Treatment options have focused on conservative management for the straightforward, smaller lesions (<5 cm), with resection preferred for larger lesions (>5 cm) that pose a greater risk of hemorrhage or malignant progression. In recent years, a new molecular subclassification of HCA has been proposed, associated with characteristic morphological features and loss or increased expression of immunohistochemical markers. This subclassification could possibly provide considerable benefits in terms of patient stratification, and the selection of treatment options. In this review we discuss the decision-making processes and associated risk analyses that should be made based on lesion size, and subtype. The usefulness of this subclassification system in terms of the procedures instigated as part of the diagnostic work-up of a suspected HCA will be outlined, and suitable treatment schemes proposed.

Argininosuccinate synthase 1 (ASS1): A marker of unclassified hepatocellular adenoma and high bleeding risk

“…As reported, the present study confirms that the risk of bleeding is exceedingly high. In our UHCA series, 41.1% (7 of 17) present an acute bleeding syndrome.…”

“…According to the recent literature, hemorrhage in HCA has been observed in 27.2% of all patients, and acute rupture and intraperitoneal bleeding were reported in 17.5% of patients . Hemorrhage generally arose in the larger lesions (>5 cm), although smaller lesions could also bleed with a frequency range of 8.3%‐11.5% .…”

“…Hepatocellular adenomas (HCAs) are rare benign tumors . The risk of complications, such as hemorrhage (26%) or malignant transformation to hepatocellular carcinoma (HCC) (7%), is higher when the tumors are larger than 5 cm leading to the recommendation to resect when the HCA reaches that size . Based on clinical, radiological, histological, immunohistochemical (IHC), and molecular features, HCA are classified into three major groups .…”

“…(1,2) The risk of complications, such as hemorrhage (26%) (3) or malignant transformation to hepatocellular carcinoma (HCC) (7%), (4) is higher when the tumors are larger than 5 cm leading to the recommendation to resect when the HCA reaches that size. (5)(6)(7) Based on clinical, radiological, histological, immunohistochemical Abbreviations: ASL, argininosuccinate lyase; ASS1, argininosuccinate synthase; b-HCA, b-catenin mutated HCA; b-IHCA, b-catenin mutated and inflammatory HCA; BMI, body mass index; CP, carbamyl phosphate; CPS1, carbamoyl phosphate synthetase I; CRP, C-reactive protein; FFPE, formalin-fixed and paraffin-embedded; FNH, focal nodular hyperplasia; GS, glutamine synthetase; HCAs, hepatocellular adenomas; HCC, hepatocellular carcinoma; H&E, hematoxylin and eosin stain; H-HCA, HNF1A mutated HCA; HNF1A, hepatocyte nuclear factor 1A; IHC, immunohistochemistry; IHCA, inflammatory HCA; LC-MS/MS, liquid chromatography/tandem mass spectrometry; LFABP, liver-type fatty acid binding protein; NO, nitric oxide; NOS, nitric oxide synthase; NT, nontumoral; OTC, ornithine transcarbamylase; SAA, serum amyloid A; shHCA, sonic hedgehog HCA; T, tumoral; UHCA, unclassified HCA.…”

Unexpected discovery of small HNF1α‐inactivated hepatocellular adenoma in pathological specimens from patients resected for liver tumours

“…Schematic representation of micro/small HNF 1α‐inactivated hepatocellular adenoma (H‐ HCA ) associated with H‐ HCA , or other types of nodules . 1‐4: the number and size of H‐ HCA vary from detectable to undetectable by imaging: solitary, multiple, adenomatosis . 5‐8: micro/small H‐ HCA not detectable by imaging but observed on the resected specimen: their number depends on the size of the specimen (tumourectomy, segmentectomy, right or left hepatectomy) and usually on the number of detected H‐ HCA on imaging: from 0 to rare associated with H‐ HCA depicted in box 1; from 0 to many associated with H‐ HCA depicted in box 2 and 3; from 0 to myriads associated with H‐ HCA depicted in box.…”