Focal nodular hyperplasia on accessory lobe of the liver: preoperative diagnosis and management

Pedunculated Focal Nodular Hyperplasia: When in Doubt, Should We Cut It Out?

Focal nodular hyperplasia (FNH) is the second most common benign hepatic tumor and can rarely present as an exophytic solitary mass attached to the liver by a stalk. Most FNH cases are usually detected as incidental findings during surgery, imaging or physical examination and have a high female predominance. However, the pedunculated forms of FNH are particularly rare and commonly associated with severe complications and diagnostic challenges. Hence, our study aims to provide a comprehensive summary of the available data on the pedunculated FNH cases among adults and children. Furthermore, we will highlight the role of different therapeutic options in treating this clinical entity. The use of imaging techniques is considered a significant addition to the diagnostic toolbox. Regarding the optimal treatment strategy, the main indications for surgery were the presence of symptoms, diagnostic uncertainty and increased risk of complications, based on the current literature. Herein, we also propose a management algorithm for patients with suspected FNH lesions. Therefore, a high index of suspicion and awareness of this pathology and its life-threatening complications, as an uncommon etiology of acute abdomen, is of utmost importance in order to achieve better clinical outcomes.

Focal nodular hyperplasia on an accessory liver lobe: A case report and literature review

INTRODUCTION

Accessory liver lobe (ALL), an autonomous island of normal liver parenchyma, is a rare congenital anomaly that is difficult for preoperative diagnosis and often identified incidentally. It can also be accompanied with benign or malignant diseases, which is extremely rare. There are only 3 cases of focal nodular hyperplasia (FNH) detected on ALL reported by previous literature.

PATIENT CONCERNS

A 33-year-old woman was incidentally diagnosed with a mass in left upper quadrant abdomen by a routine ultrasound examination. Doppler ultrasound revealed that the mass was attached to left liver lobe with a vascular pedicle. A spoke-wheel artery with diffuse enhancement during hepatic arterial phase was visualized on contrast-enhanced ultrasound, and the mass was continuously hyper-enhanced with a hypo-enhanced intralesional scar during the portal and delayed phase. And contrast-enhanced computed tomography showed a similar enhancement mode of the mass.

DIAGNOSIS

The mass was resected and postoperative histopathologic result of the lesion revealed a nodular hyperplastic parenchyma with a central fibrous scar, without tumor cells. And a final diagnosis of FNH on ALL was determined accordingly.

INTERVENTIONS

Mass resection was conducted according to patient's demand.

OUTCOME

After general postoperative administration, the patient was discharged. Then, she had been undergoing regular serological tests and imaging examinations in our hospital for 24 months.

CONCLUSION

The finding of a mass connecting with liver by a stalk should alert the clinician of the possibility of ALL, as well as benign or malignancies on an ALL. This is the first case of FNH on ALL preoperatively confirmed by contrast-enhanced ultrasound. We suggest that an integrated radiologic approach is crucial to evaluate an incidentally detected, asymptomatic abdominal focal mass.

Hepatocellular carcinoma arising from left accessory liver lobe supplied by the branch of left hepatic artery: A case report

INTRODUCTION

Accessory liver lobe (ALL) is a rare congenital anomaly. ALL combined with hepatocellular carcinoma (HCC) is even rarer. Most ALLs with HCC are often located in the right liver, and are not supplied by the left hepatic artery.

PATIENT CONCERNS

A 77-year-old man was referred to our hospital because of the level of serum alpha-fetoprotein (AFP) continually increased for 1 month. He had no history of chronic hepatitis, alcohol abuse, or cirrhosis of the liver.

DIAGNOSES

Preoperative computed tomography (CT) scan revealed a 3.0 × 3.0 × 1.0 cm ovaloid-shaped solid mass in the left subphrenic area with isodensity. Magnetic resonance imaging (MRI) showed a mass with a heterogeneous signal on T1- and T2-weighted images. On contrast-enhanced CT and MRI, the mass showed a pattern of early enhancement and washout. Digital subtraction angiography (DSA) confirmed the mass was fed by the branch of left liver artery.

INTERVENTIONS

The mass was treated by transatheter arterial embolization (TAE) followed by surgical resection. Histopathologically showed HCC, consistent with a moderately differentiated.

OUTCOMES

Follow-up of 3 months after surgery, the level of AFP returned to normal gradually.

CONCLUSIONS

In this report, we describe a rare case of ALL with HCC, located in the left subphrenic area, especially which was supplied by the branch of left hepatic artery has rarely been described. The clinical presentation, radiological features are described in the literature.

Morphometric analyses of small accessory liver lobes using radiological imaging

AIM

To investigate the prevalence and morphometric characteristics of small accessory liver lobes using computed tomography (CT) and magnetic resonance (MR) images.

MATERIAL AND METHODS

The study population comprised 3269 patients (1671 men and 1598 women; mean age, 67.1 ± 15.2 years) who had undergone abdominal CT examination. Small accessory liver lobes were identified after verification of their continuity with the liver parenchyma on CT images. Their imaging characteristics were analyzed and presented.

RESULTS

Thirty-five small accessory liver lobes in 33 patients (1.01%; 25 men and 8 women, 71.0 ± 11.7 years) were identified. Thirty-one patients (93.9%) had solitary lesions most frequently identified on liver segment 6 (80.0%) with the mean size 9.6 ± 4.8 mm. These showed iso (62.9%), hyper (28.6%), or hypoattenuation (8.6%) on unenhanced CT. Enhanced CT images were available for 29 lesions. Enhancement of 12 lesions (41.4%) was similar to that of the liver parenchyma, whereas 17 lesions (58.6%) showed poor enhancement. MR images were available for 10 lesions, which showed hyperintensity (50.0%) on T2-weighted images and poor enhancement (50.0%). The characteristics of other lesions were similar to those of the liver parenchyma. During observation (mean, 77.0 months; n = 29), 19 lesions remained the same size (65.5%), 5 new lesions increased size (17.2%), and 5 showed reduced size (17.2%).

CONCLUSION

Small accessory liver lobes, commonly located on segment 6, were frequently observed and did not necessarily show the same findings as the liver parenchyma. Time-dependent morphological changes were observed in approximately one-third of the lesions.

Radiographic, ultrasonographic, and computed tomographic characteristics of an accessory liver lobe in a cat

A 5-year-old male Norwegian Forest cat presented with increased hepatic serum biochemical parameters. Abdominal radiography showed an oval cranioventral mass and ultrasound revealed a mobile mass attached to one hepatic lobe. Computed tomography (CT) confirmed that the mass was attached to the right medial liver lobe. Differential diagnoses were an accessory liver lobe, benign neoplasia, and focal nodular hyperplasia. The mass was removed and histopathology confirmed the mass to be normal liver tissue. Accessory liver lobe should be included in the differential diagnosis of a mobile cranial abdominal mass with a similar ultrasonographic or CT appearance to the liver.

Accessory liver lobe of the gallbladder in adults

The accessory liver lobe (ALL) of the gallbladder wall is rare, mentioned by Meckel since 1822. We present two cases of ALL occurring in two adult women. The ALLs were diagnosed at microscopic examination of cholecystectomy specimens for lithiasic cholecystitis and were located at the gallbladder body level. They measured 0.5 and 1.1 cm and were pediculated from the gallbladder serosa. Luschka duct complexes were seen in the adjacent subserosa in one of the cases. The main clinical relevance of ALL of the gallbladder resides in the differential diagnosis with a lymph node and in the risk of peroperative hemorragia or bile leakage by sectioning of the connecting blood vessels and/or bile duct. Intraparietal ALL may interfere with dysmotility, possibly resulting in bile stagnation and stone formation.