Focal Nodular Hyperplasia (FNH) is a benign, hyperplastic nodular lesion in the liver, usually seen in non-cirrhotic livers, but occasionally in patients with cirrhosis. Although the pathogenesis of FNH is controversial, it is commonly thought to be an abnormal proliferative response due to pre-existing localized vascular malformations within the liver, resulting in increased arterial blood flow to specific areas, elevated hepatic sinusoidal pressure, and abnormal hepatocyte hyperperfusion. In recent years, with the development of imaging and the emphasis on health screening, it is often found incidentally on abdominal imaging or during physical examination.FNH is a benign lesion, usually occurring in the context of a healthy liver but presenting as a tumor-like hyperplastic nodule, and therefore there is controversy regarding the principles of treatment for FNH, especially whether to use surgical treatment or just observation. The author will discuss several issues of concern in FNH to analyze the treatment options for FNH. I. Whether imaging can confirm the diagnosis of FNH The fear of misdiagnosis of FNH is to a large extent, especially the fear of missing the diagnosis of hepatocellular carcinoma. However, in imaging, the majority of FNH has a typical presentation with imaging features related to central scarring, rich blood supply and unique arterial supply, often seen radiating from the center with bifurcated peripheral spoke-like changes. In enhanced MRI, FNH usually appears as a homogeneous lesion with isosignal or mildly low signal on T1-weighting and equal to mildly high signal on T2-weighting, with not very well-defined borders and a central scar visible on T2-weighting in approximately 50% of cases. If enhanced with gadolinium agent, the lesion shows early homogeneous enhancement in the arterial phase and equal or mild high signal in the venous and delayed phases. The most characteristic feature is the slow progressive enhancement of the central scar, which is maximized in the delayed phase. Another distinguishing feature is the absence of envelope on FNH enhancement, whereas hepatocellular adenoma and hepatocellular carcinoma are usually seen with envelope. However, it should be noted that small FNH lesions (<1-2 cm) can show very uniform enhancement with no central scar visible, but they can often be differentiated from hepatocellular carcinoma and others based on other enhancement features. Another concern of patients after diagnosis is whether FNH will gradually increase in size and cause more serious clinical consequences such as compression and rupture. There are few longitudinal, long-term follow-up studies. In one study of 18 cases of FNH, 6 cases were unchanged in size, 10 cases decreased in size, and only 2 cases increased in size. In another longitudinal ultrasound follow-up study of 36 cases, the mean follow-up was 42 months, and 70.6% of the lesions were stable, 26.5% were reduced in size, and only 2.9% were increased in size. The author also observed some outpatient follow-up cases of FNH in the clinic, and many lesions did not show a significant trend of enlargement after years of follow-up. From the available studies, FNH and hepatocellular carcinoma are two completely different diseases, and there is no evidence to suggest that FNH is a precancerous lesion of hepatocellular carcinoma or fibrous lamellar hepatocellular carcinoma. However, it is important to be alert to the possible coexistence of FNH with hepatic adenoma (which can be cancerous). I have treated a patient with multiple FNH-like lesions in the liver, and the postoperative pathology suggested that the lesions in the left lobe of the liver were hepatic adenoma and the lesions in the right lobe of the liver were FNH. There are even very rare clinical reports that found that FNH and hepatocellular carcinoma lesions can coexist in the same lesion, with clinical features such as rapidly enlarging lesions and heterogeneous MRI performance. On the other hand, intensified nodules on the basis of cirrhosis are not highly suspicious of hepatocellular carcinoma, especially on the basis of Bu-plus syndrome, etc., and it is very common to find multiple FNH and other lesions. IV. Clinical treatment options for FNH In summary, in FNH that is more typical on clinical imaging, in the vast majority of cases, only clinical observation is required and no surgical or other therapeutic intervention is needed. Surgical treatment is generally considered only in the following cases: 1, FNH masses that are huge and cause obvious clinical symptoms; or those located in the hilar region and cause relevant clinical manifestations by compression of intrahepatic ducts. 2, those that cannot be differentiated from hepatocellular carcinoma (including fibrous lamellar-like hepatocellular carcinoma) on imaging, but need to be identified after consultation at an experienced imaging center. 3, those that cannot be excluded from hepatocellular carcinoma, hepatic adenoma and other malignant (including potentially malignant) lesions when they coexist, surgical intervention is required, but this is extremely rare.