Histologic scoring of liver biopsy in focal nodular hyperplasia with atypical presentation

Abstract

The contribution of radio-guided transcutaneous biopsy in the diagnosis of focal nodular hyperplasia (FNH) of the liver was compared with the findings on surgical specimens to assess its contribution in clinical and radiologic atypical cases. This retrospective study involved 30 patients with atypical tumors on imaging who underwent liver biopsy and then surgery. All surgical specimens were diagnosed as FNH, either classical (n ‫؍‬ 18) or nonclassical (n ‫؍‬ 12). Imaging data were reviewed according to 4 radiologic criteria on magnetic resonance imaging (MRI) and/or computed tomography (CT) scan (hypervascularity, homogeneity, nonencapsulation, and presence of a central scar), and classified depending on the number of criteria found (group I, 4 of 4; group II, 3 of 4; group III, 2 or fewer). Histologic assessment of ultrasound (US)-guided liver biopsy recorded major diagnostic features (fibrous bands, thick-walled vessels, reactive ductules, and nodularity) and minor features (sinusoidal dilatation and perisinusoidal fibrosis). "Definite FNH" (3 or 4 major features) was diagnosed in 14 biopsies, "possible FNH" (2 major and 1 or 2 minor features) in 7 cases, and "negative for FNH" (2 or fewer major features without minor features) in 9 cases. The diagnosis of FNH on biopsy was reached in 14 cases (58.3%) in patients with 2 or fewer imaging criteria (group III; n ‫؍‬ 24). Biopsies with a diagnosis of "possible FNH" corresponded to a large proportion of telangiectatic-type FNH on the specimen. In conclusion, liver biopsy does not appear to be necessary in cases in which imaging is typical. However, the absence of radiologic diagnostic criteria in FNH does not preclude a positive diagnosis on liver needle biopsy. Using the proposed histologic scoring system, surgical management may be avoided in these cases. (HEPATOLOGY 2002;35:414-420.) F ocal nodular hyperplasia (FNH) of the liver is a benign disorder that usually occurs in women of childbearing and middle age. Numerous terms have been used to designate this entity, 1 reflecting the different morphologic aspects and the confusion that currently exists regarding its pathogenesis, which is thought to be hyperplastic, rather than neoplastic, in nature. 2 A liver nodule with a central fibrous scar containing aberrant vessels of various size and thickness and reactive ductules surrounded by abnormal regenerative hepatocyte nodules 3 characterizes the classical form of FNH, as originally described by Edmonson. 4 A previous study on surgical specimens described nonclassical forms of this lesion: all lacking the central scar but in which parenchymal nodularity and vascular anomalies were still the main features. 5 In classical cases, the diagnosis is usually made easily using radiologic criteria either on computed tomography (CT) scan or magnetic resonance imaging (MRI). 6,7 These criteria include hypervascularity with enhancement during arterial phase, homogeneity of the lesion, nonencapsulation, and the presence of a central scar. Conservative management of FNH is curre...

Research on focal nodular hyperplasia with MSCT and postprocessing

“…The FNH pathology has 3 major characteristics: (1) The pathological change is not a real tumor, but mainly normally functioning hepatic cells, with proliferation of the connectivum, the abnor mal bile duct and macrophages; (2) The existence of abnormal blood vessels and fiber structure, namely a scar in the center of the pathological change; (3) The blood supply pattern radiated from the inside to the periphery [12][13][14] . Under the microscope may be seen fibrous divisions and an area of proliferating hepatic cells in FNH, which lacks a normal vein and portal vein, and sometimes has acute or chronic inflammatory cells [15] .…”

Diagnosis and management of hepatic focal nodular hyperplasia

“…In fact, cytology alone may not be sufficient to distinguish FNH from well-differentiated hepatocellular carcinoma or adenoma. Uncertainties are especially likely to arise in atypical variants that lack a central scar or other typical imaging findings [85], and in these cases, the best solution is histologic analysis of an ultrasound-guided biopsy specimen. To reach the nodule, the needle has to pass through at least 1 cm of normal hepatic parenchyma.…”

Evaluation of Hepatic Focal Nodular Hyperplasia With Contrast-Enhanced Gray Scale Harmonic Sonography

“…A recent pathologic study claimed that liver biopsy in the treatment of FNH is not necessary if imaging findings are typical. 28 Unfortunately, pathologic examination of a specimen obtained with sonographically guided biopsy does not always characterize FNH. Indeed, it is well known that FNH and cirrhotic liver have similar histologic features (fibrous bands, abnormal vessels, and reactive ductules).…”

“…Indeed, it is well known that FNH and cirrhotic liver have similar histologic features (fibrous bands, abnormal vessels, and reactive ductules). 28 Hepatic adenoma is characterized by hepatocytes arranged in plates that are 2 to 3 cells thick, separated by slitlike sinusoids, which are occasionally dilated. These features, however, can also be observed in telangiectatic FNH.…”