Strange Taylor, Gosnell Joseph M, Bhargava Peeyush, Al Harbi Abdulrahman, Cicalese Luca, Stevenson Heather L
Department of Pathology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
Department of Radiology, University of Texas Medical Branch, Galveston, USA.
Diagn Pathol. 2025 May 30;20(1):69. doi: 10.1186/s13000-025-01661-y.
Focal nodular hyperplasia (FNH) is a benign hepatic lesion that rarely presents as an exophytic mass attached by a fibrous stalk (termed pedunculated FNH). This variation poses a challenge to clinicians, with atypical symptoms and imaging.
We describe a 33-year-old female who underwent excision of a pedunculated FNH. On gross examination, the lesion was lobular and vascular with homogenous tan-brown surfaces. Histological examination showed loss of normal liver architecture, abnormal intervening fibrous tracts, dysplastic arteries, and focal steatosis. Immunohistochemical staining with glutamine synthetase resulted in a branching, or "map-like" pattern. These findings were consistent with focal nodular hyperplasia. One of the most sensitive imaging techniques for diagnosing this lesion involves magnetic resonance imaging (MRI) with contrast, which discloses a homogenous mass that is hyperintense during the arterial phase with gradual decrease in intensity during the venous and equilibrium phases. The central stellate scar will often remain hyperintense for a prolonged period of time. On histology, normal hepatic architecture is lost to abnormal fibrotic bands and a characteristic stellate scar. Immunohistochemistry with glutamine synthetase uniquely highlights a map-like pattern that is not seen in other liver lesions.
Due to its atypical presentation and increased risk of complications compared to its intrahepatic counterpart, pedunculated FNH brings unique challenges for diagnosis and therapy. Proper identification of pedunculated FNH is critical for appropriate treatment. Our case highlights the importance of radiological and histopathological studies to accurately identify this lesion, as well as the benefits of surgical removal to prevent serious complications.
局灶性结节性增生（FNH）是一种良性肝脏病变，很少表现为通过纤维蒂附着的外生性肿块（称为带蒂FNH）。这种变异给临床医生带来了挑战，其症状和影像学表现不典型。
我们描述了一名33岁接受带蒂FNH切除手术的女性。大体检查时，病变呈小叶状且血管丰富，表面为均匀的棕褐色。组织学检查显示正常肝结构消失，有异常的间质纤维束、发育异常的动脉和局灶性脂肪变性。谷氨酰胺合成酶免疫组化染色呈现分支状或“地图样”图案。这些发现符合局灶性结节性增生。诊断该病变最敏感的影像学技术之一是增强磁共振成像（MRI），其显示一个均匀的肿块，在动脉期呈高信号，在静脉期和平衡期信号强度逐渐降低。中央星状瘢痕通常会在较长时间内保持高信号。在组织学上，正常肝结构被异常纤维化带和特征性星状瘢痕取代。谷氨酰胺合成酶免疫组化独特地突出了一种在其他肝脏病变中未见的地图样图案。
由于其表现不典型且与肝内型相比并发症风险增加，带蒂FNH在诊断和治疗方面带来了独特的挑战。正确识别带蒂FNH对于恰当治疗至关重要。我们的病例强调了放射学和组织病理学研究对于准确识别该病变的重要性，以及手术切除预防严重并发症的益处。
