What's in A Name? (2009)

E. M. Brunt illustrated in her article focusing on nonalcoholic fatty liver disease (NAFLD) the difficulty in giving names to complex entities which are not, or cannot be, fully characterized, particularly when it comes to the combination of pathological/clinical and prognostic criteria.1 Here, we discuss another issue illustrating the confusion of terms. This concern is minor in terms of public health, but a source of diagnostic problem for liver specialists and important for patients who develop benign hepatocellular nodules. Focal nodular hyperplasia (FNH) is believed to be a nonspecific response to locally increased blood flow. In 1989, Wanless et al. described an entity they called telangiectatic focal nodular hyperplasia (TFNH) occurring in the multiple FNH syndrome as well as in a minority of patients with solitary FNH.2 They mentioned without detail that at the microscopic level, lesions were similar to those observed in hereditary hemorrhagic telangiectasia (HHT). Ten years later, Nguyen et al. described lesions classified as FNH of telangiectatic form.3 At the microscopic scale, the hepatic plates were separated by sinusoidal dilatation, sometimes alternating with areas of marked ectasia. In 2004, Paradis et al. showed that the molecular profile of the TFNH at the DNA, gene, and protein expression level was more similar to that of hepatocellular adenomas (HCAs) than that of typical FNH. Telangiectasia was defined at the microscopic level as areas of sinusoidal dilatation, congestion, and peliosis. They suggested that these lesions should be considered to be “telangiectatic HCA” (THCA).4 In 2005, Bioulac-Sage et al. reached the same conclusion using different molecular techniques5 and included in 2007 the so-called “TFNH” in the subgroup of inflammatory HCAs.6 Finally, in 2009, the basis of the inflammatory phenotype was elucidated by the identification of the mutations activating gp130 in most of the inflammatory HCAs exhibiting sinusoidal dilation or not.7 In 2009, several liver pathologists are still convinced that in addition to inflammatory HCA, which includes so-called “TFNH”, FNH with major sinusoidal dilatation still exists (Fig. 1). Biopsy of a hepatocellular nodule with areas of major sinusoidal dilatation (*). Glutamine synthetase staining (GS) confirms the diagnosis of FNH.9 H&E, hematoxylin and eosin. In an attempt to clarify the terminology, we propose to avoid the term telangiectasia to define the different pathological types of FNH and HCA because it is confusing and inappropriate. According to Merriam-Webster's Medical Dictionary, telangiectasia (plural: telangiectasias or telangiectases), which is an abnormal dilatation of capillary vessels and arterioles that often forms an angioma, is a term used in HHT. HHT is characterized by widespread liver arteriovenous malformations, both microscopic and macroscopic, ranging from tiny telangiectases to discrete arteriovenous malformations. Upon computed tomography scan analyses, round and highly enhanced lesions with a diameter of less than 10 mm and a prevalently peripheral arrangement are considered parenchymal hepatic telangiectases.8 The combination of immunohistochemistry markers of the HCA genotype/phenotype classification,6 including glutamine synthetase,9 allows the possible identification of the great majority HCA subtypes. It also allows for differential diagnosis between HCA and FNH independently of the presence or absence of sinusoidal dilatation, congestion, and peliosis, which are all terms abusively condensed under the name telangiectasia, at least in HCA where there are no vascular shunts. However, a major clinical issue still remains. Indeed, can imaging, and if necessary liver biopsy, identify the type of hepatocellular nodule with major sinusoidal dilatation/congestion/peliosis? If it is a FNH, could it bleed? More than ever, the detection and characterization of hepatocellular nodules requires appropriate tools including immunohistochemistry6, 9 and, if necessary, molecular techniques.6, 10 Paulette Bioulac-Sage*, Charles Balabaud , Jessica Zucman-Rossi , * Service d'Anatomie Pathologique,Hôpital Pellegrin Centre Hospitalier Universitaire (CHU) Bordeaux, Institut National de la Santé et de la Recherche Médicale (Inserm), U889, Université Bordeaux 2, Bordeaux, France, Service d'Hépatologie, Hôpital St André CHU Bordeaux, Inserm, U889, Université Bordeaux 2 Bordeaux France, Inserm, U674, Université Paris Descartes, Assistance Publique–Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Paris, France.