Plexiform neurofibroma of the liver: findings on mr imaging, angiography, and CT portography

Neurofibromatosis Type 1 with a Giant Diffuse Plexiform Neurofibroma Invading the Liver

Plexiform neurofibromas (PNs) occur in approximately 50% of patients with neurofibromatosis type 1 (NF1). PNs are rare in the abdominal cavity and especially rare in hepatobiliary lesions. A 31-year-old man with NF1 had a tumor extending along the celiac artery, superior mesenteric artery, and intrahepatic portal vein. We diagnosed him with diffuse PN based on liver tumor biopsy findings and the tumor form. Because the tumor had invaded along the intrahepatic portal vein, surgical resection was deemed difficult, and the patient was followed up with imaging studies. The patient remained asymptomatic without tumor growth.

Portal cavernoma in type 1 neurofibromatosis: A fortuitous or causal association?

Neurofibromatosis type 1 (NF-1) is a multisystem genetic disorder affecting the NF1 tumor suppressor gene. Patients typically develop superficial (cutaneous) and internal (plexiform) neurofibromas. The latter may rarely involve the liver locating in the hilum and encasing the portal vessels, leading to portal hypertension. Vascular abnormalities (NF-I vasculopathy) are a well-recognized manifestation of NF-1. Although the pathogenesis is not well-known, NF-1 vasculopathy involves arteries of both peripheral and cerebral territories, with venous thrombosis being exceptionally reported. Portal venous thrombosis (PVT) is the leading cause of portal hypertension in childhood and has been associated with several risk factors. Nevertheless, predisposing conditions remain unknown in more than 50% of the cases. The treatment options are limited, and its management is nonconsensual in the pediatric age. We report the case of a 9-year-old boy with clinically and genetically confirmed NF-1, diagnosed with portal venous cavernoma after an episode of gastrointestinal bleeding. There were no identifiable risk factors for PVT and intrahepatic peri-hilar plexiform neurofibroma was excluded by MRI imaging. To the best of our knowledge, this is the first report of PVT in NF-1. We speculate that NF-1 vasculopathy may have been a pathogenic factor, or instead, it was a fortuitous association.

Intranodal Neurofibroma: A Case Report and Literature Review

PURPOSE

To report a case of neurofibroma involving the lymph nodes and to perform a literature review on this topic.

OBSERVATIONS

A 72-year-old woman with a history of neurofibromatosis and biopsy-proven malignant melanoma of the left forearm underwent wide local excision of the malignant lesion along with sentinel axillary lymph node biopsy. Histological examination of axillary nodes revealed diffuse neurofibromatosis within 2 lymph node capsules. A thorough review of the English literature pertaining to intranodal neurofibroma was performed by querying Google Scholar and PubMed. Only 5 cases of intranodal neurofibroma have been described until now.

CONCLUSIONS AND IMPORTANCE

Neurofibroma involving the lymph nodes is rare and this is the first reported case that is shown to diffusely involve the intracapsular space. Furthermore, intranodal neurofibroma can represent a diagnostic pitfall in the evaluation of sentinel lymph nodes for metastatic melanoma.

A rare case of plexiform neurofibroma of the liver in a patient without neurofibromatosis type 1

Plexiform neurofibroma is mainly associated with neurofibromatosis type 1 and is seldom observed in the liver. Its occurrence in the liver without neurofibromatosis type 1 is even rarer. We report an extremely rare case of plexiform neurofibroma of the liver diagnosed by laparoscopic biopsy in a patient without neurofibromatosis type 1. The patient was a 35-year-old man who had neither clinical signs nor any family history of neurofibromatosis type 1. Abdominal ultrasonography, as part of a health screening, had detected a hepatic tumor. Subsequent contrast ultrasonography, computed tomography, and magnetic resonance imaging showed the tumor extending from the retroperitoneal space around the aorta to the hepatic hilum and distal portal branches in the right hepatic lobe, gallbladder, and left hepatic lobe. ¹⁸F-fluorodeoxyglucose positron emission tomography showed no abnormal accumulation. Histopathological examination of the tumor obtained laparoscopically led to a diagnosis of plexiform neurofibroma. Because the patient was asymptomatic with no features of malignancy, he was only monitored and managed. At follow-up 10 years later, computed tomography showed a decrease in tumor size. It is important to recognize that, while rare, plexiform neurofibroma can occur without neurofibromatosis type 1. We recommend follow-up instead of unreasonable surgery in such cases.

Nonoperative Management May Be a Viable Approach to Plexiform Neurofibroma of the Porta Hepatis in Patients with Neurofibromatosis-1

Background

Plexiform neurofibroma (PNF) in the porta hepatis (PH) is an unusual manifestation of neurofibromatosis-1 (NF-1). Resection is often recommended given the risk of malignant transformation. We encountered a challenging case in clinical practice which prompted us to report our findings and perform a systematic review on the management of these tumors.

Methods

We reported the case of a 31-year-old woman with NF-1 and PNF of the PH. PRISMA 2009 guidelines were followed for systematic review.

Results

Our patient was found to have unresectable disease at exploration. After >5 years of follow-up, she continued to have stable disease on imaging. We identified 12 studies/case reports including 10 adult and 6 pediatric patients with PNF of PH. None of the 7 adult patients with NF-1 and PNF of PH underwent a successful tumor resection. All pediatric patients were managed with surveillance alone. All but one pediatric patient had NF-1. None of the reported cases of PNF of PH had malignant transformation.

Conclusion

Our findings suggest that PNFs of PH in the setting of NF-1 are often unresectable and may have an indolent course. Surveillance alone may be a reasonable option in some patients; however, further studies are needed.

Hepatic, Periportal, Retroperitoneal, and Mesenteric Neurofibromatosis in von Recklinghausen's Disease

We present a rare case of histologically proven neurofibromatosis of the liver, hepatic hilum, retroperitoneum, and mesentery. An adult male who had been diagnosed with neurofibromatosis (NF) type 1 underwent a computed tomography (CT) scan for abdominal pain and vomiting. The CT scan showed a large low-attenuating lesion in the region of porta hepatis which was infiltrating along portal tracts into the liver, encasing the major vessels, and extending into the retroperitoneum and mesentery. Based on the radiological findings, a differential diagnosis of plexiform neurofibroma was given, although sarcomatous transformation could not have been entirely excluded from imaging alone. The tumor was subsequently biopsied, and the histopathological analysis confirmed the diagnosis of neurofibroma. This case highlights the importance and diagnostic dilemmas in the presence of this tumor at atypical locations in this disease spectrum.

Primary mesenchymal liver tumors: radiological spectrum, differential diagnosis, and pathologic correlation

With the exception of hemangioma, benign or malignant primary mesenchymal tumors of the liver are seldom encountered. The aim of this review was to discuss the clinical, histopathological, and imaging features of liver hemangiomas (cavernous, capillary, and sclerosed types), liver lipoma, angiomyolipoma, mesenchymal hamartoma, neurofibroma, infantile hemangioendothelioma, epithelioid hemangioendothelioma, myofibroblastoma, angiosarcoma, malignant fibrous histiocytoma, undifferentiated embryonal sarcoma, and nested stromal tumor. In most of these rare liver tumors, radiological findings obtained by cross-sectional imaging may reflect the characteristic pathologic features required for differential diagnosis; however, definitive diagnosis should be confirmed using histopathological examination.

"Periportal neoplasms"--a CT perspective: review article

The periportal space is a potential space surrounding the portal vein and its intrahepatic branches. A variety of neoplasms can involve the periportal region, whether primary or secondary, owing to contiguous spread from surrounding hepatic parenchyma or from adjacent organs. CT plays an important role in not only diagnosing these lesions but also determining the extent of the disease. Most of the malignancies leading to the periportal spread manifest as periportal hypodensity either distinctly or in contiguity with the primary tumour. Even in known malignancies, periportal hypodensity commonly results from non-neoplastic causes like periportal oedema; hence, a knowledge of the imaging findings to ascertain its presence as well as to conclude the definite neoplastic spread is prudent. Periportal spread of neoplasm may suggest locally aggressive or disseminated disease (in extrahepatic malignancies), which may change management accordingly.

MRI of common and uncommon pathologies involving the periportal space: a pictorial essay

Imaging detection and differential diagnoses of pathology involving the periportal space can be challenging. MRI is a useful technique for assessment of the periportal space since it readily distinguishes normal and abnormal vascular and biliary anatomy, and the excellent soft tissue discrimination allows for detection of subtle lesions. This pictorial essay describes the anatomy of the periportal space and illustrates the MRI appearance of a variety of pathologies that can affect this region.

Imaging of the porta hepatis: spectrum of disease

A wide array of pathologic conditions can arise within the porta hepatis, which encompasses the portal triad (the main portal vein, common hepatic artery, and common bile ducts), lymphatics, nerves, and connective tissue. Major vascular diseases of the portal triad include thrombosis, stenosis, and aneurysm. Portal vein thrombosis can complicate liver cirrhosis and hepatocellular carcinoma and has important therapeutic implications. Hepatic artery thrombosis and stenosis require immediate attention to reduce graft loss in liver transplant recipients. Congenital (eg, choledochal cyst) and acquired (benign and malignant) diseases of the biliary system can manifest as mass lesions in the porta hepatis. Lymphadenopathy can arise from neoplastic and nonneoplastic entities. Uncommon causes of mass lesions arise from nerves (eg, neurofibroma, neurofibrosarcoma) and connective tissue (sarcomas) and are rare. The hepatoduodenal ligament is a peritoneal reflection at the porta hepatis and is an important route for the spread of pancreatic and gastrointestinal cancers. Imaging plays a major role in diagnosis and enables appropriate management. Ultrasonography accurately demonstrates anatomic variations and pathologic conditions and is the initial modality of choice for detection of vascular and biliary lesions. Multidetector computed tomography and magnetic resonance imaging allow characterization and differentiation of various masses in the porta hepatis. Imaging-guided interventions, including embolization and stent placement, also play a key role in disease management.

MRI features of plexiform neurofibromas involving the liver and pancreas in children with neurofibromatosis type 1

AIM

To describe magnetic resonance imaging (MRI) findings of plexiform neurofibromas (PNF) involving the liver and pancreas in paediatric patients with neurofibromatosis type 1 (NF1).

MATERIALS AND METHODS

A retrospective search of the hospital database was undertaken to find cases of PNF in the porta hepatis, hilar neurofibroma, and hepatic neurofibroma over a 12 year period. The images were analysed and a review of the charts was undertaken.

RESULTS

Five paediatric patients were identified with extensive PNFs involving the liver. In all cases, the PNFs involved the liver along the intrahepatic portal distribution. Additionally, the gallbladder fossa was affected in 2/5 patients, the pancreatic head in 4/5 patients, the pancreatic neck in 2/5 patients, and the pancreatic tail in 1/5 patients. All tumours showed low signal intensity (SI) on T1-weighted images and high SI with a central target sign on water-sensitive sequences. No patient showed any signs or symptoms, nor required treatment or surgery related to hepatic or pancreatic involvement. Intrahepatic PNFs were stable over a median follow-up time of 3.6 years (range 3 months to 8.8 years).

CONCLUSIONS

Intrahepatic and pancreatic involvement, although rare, does occur in paediatric NF1 patients. The MRI findings of the tumour are similar to the PNFs that occur more commonly elsewhere in this population. The hallmark of liver involvement is the periportal distribution.

Diagnosis and management of an isolated pediatric plexiform neurofibroma involving the hepatic and celiac plexus using multimodality approach: problem solving with diffusion-weighted magnetic resonance imaging

Plexiform neurofibroma with involvement of the gastrointestinal tract is a very rare entity in children. Here, we present a rather unique case of a 9-year-old boy with no clinical signs or features of neurofibromatosis type 1. A periportal mass lesion was incidentally found after performing an ultrasound in this previously healthy child. Computed tomographic scan was subsequently performed which showed a low-density mass in a periportal distribution with extension along the celiac axis. Because the findings were nonspecific, a pre- and postcontrast magnetic resonance imaging of the abdomen was performed which included diffusion-weighted imaging. The lesion was then confirmed to be a plexiform neurofibroma with open biopsy. Management of plexiform neurofibromas varies widely. Given the extensive nature of the lesion, managing the patient with follow-up rather than surgical excision was favored.

Surgicopathological classification of hepatic space-occupying lesions: A single-center experience with literature review

Accompanying rapid developments in hepatic surgery, the number of surgeries and identifications of histological types of primary hepatic space-occupying lesions (PHSOLs) have increased dramatically. This has led to many changes in the surgicopathological spectrum of PHSOLs, and has contributed to a theoretical basis for modern hepatic surgery and oncological pathology. Between 1982 and 2009 at the Eastern Hepatobiliary Surgery Hospital (EHBH) in Shanghai, 31 901 patients underwent surgery and were diagnosed as having a PHSOL. In this paper, we present an analysis of the PHSOL cases at the EHBH for this time period, along with results from a systematic literature review. We describe a surgicopathological spectrum comprising more than 100 types of PHSOLs that can be stratified into three types: tumor-like, benign, and malignant. We also stratified the PHSOLs into six subtypes derived from hepatocytes; cholangiocytes; vascular, lymphoid and hemopoietic tissues; muscular, fibrous and adipose tissues; neural and neuroendocrine tissues; and miscellaneous tissues. The present study provides a new classification system that can be used as a current reference for clinicians and pathologists to make correct diagnoses and differential diagnoses among various PHSOLs.

Giant plexiform neurofibroma with hemorrhage in cranio-maxillofacial region as depicted on CT and MRI

Plexiform neurofibroma (PN) is a rare benign tumor and a special subtype of neurofibromatosis type 1 (NF1). Though the incidence is low, giant PN of the craniomaxillofacial region could result in severe hemifacial hypertrophy which is known as a typical manifestation of NF1 in young children. Here, we retrospectively reported a giant plexiform neurofibroma with hemorrhage in the cranio-maxillofacial region detected by CT and MRI. In addition, a brief review of the relevant literature is presented.

Plexiform neurofibroma in the hepatic hilum associated with neurofibromatosis type 1: a case report

We present an extremely rare case of plexiform neurofibroma involving the hepatic hilum. A 24-year old woman who had been diagnosed with neurofibromatosis type 1 was referred to our hospital for evaluation of an abdominal mass found on computed tomography and progressive aggravation of intermittent abdominal pain. Abdominal computed tomography revealed a multilobulated non-enhancing mass involving the celiac trunk and hepatic artery, that extended to the hepatic hilum through the hepatoduodenal ligament. Magnetic resonance imaging showed the lesion extending along the intrahepatic Glisson's sheath. Based on the imaging findings, the patient was diagnosed to have a neu-rofibroma, although sarcomatous differentiation could not be excluded. The tumor was resected, leaving behind the intrahepatic extension, with the aim of alleviating the abdominal pain and preventing obstructive jaundice. Histopathological examination revealed the diagnosis of plexiform neurofibroma. At present, three years after the surgery, the patient remains symptom-free, without any evidence of recurrence.

Obstructive jaundice secondary to neuroendocrine tumour in a patient with von Recklinghausen's disease

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder, with variable clinical manifestations and unpredictable course, associated with an increased incidence of various tumours. Plexiform neurofibromas are hallmark lesions of NF1; they are slow-growing tumours, which account for substantial morbidity, including disfigurement and functional impairment, and may even be life-threatening. Neuroendocrine tumours (NETs), a rare diverse group of neoplasms, are occasionally associated with neurofibromatosis. Pancreatic NETs are tumours with an incidence of less than 1/100 000 population/year and complex patterns of behaviour, which often need complicated strategies for optimal management. We present the case of a young adult with NF1, having a unique concurrence of plexiform neurofibroma involving the liver with an ampullary NET, and we discuss step by step the management in a specialist centre.