Case report. Schwannoma of both intrahepatic and extrahepatic bile ducts: a rare case

Schwannoma of Common Bile Duct: A Clinico-Radiologic Diagnostic Quagmire - A Case Report

Background

Schwannomas are benign nerve sheath tumors that are extremely rare in the biliary tract. A comprehensive review of literature enumerated approximately 30 case reports of schwannoma in the biliary tract tree and porta hepatis region.

Case Presentation

We report a case of a 40-year-old female who presented with abdominal pain. Imaging revealed a mass at the porta hepatis extending from the portal bifurcation till the hilum encasing the main portal vein and abutting the right portal vein. Differentials of carcinoma, lymphoma, and mesenchymal tumor were kept. Ultrasound-guided biopsy of the mass showed a benign nerve sheath tumor, immunopositive for S100. The histopathological evaluation of the excised mass confirmed the origin of mass in the common bile duct.

Conclusions

Our case highlights that schwannomas, though benign, can mimic a carcinoma or lymphoma if present at a rare site such as bile ducts. An exhaustive clinical and radiological workup with diligent histopathological evaluation is mandatory in dealing with such rare cases as radical surgery and chemotherapy can be avoided in such patients.

Biliary Schwannoma That Required Differentiation from Bile Duct Cancer

Schwannomas are benign tumors originating from Schwann cells, which are the main component of the neural sheath. Biliary schwannomas are extremely rare. We report the case of a 78-year-old man who presented with no abdominal symptoms or jaundice. CT imaging showed a hyperdense mass extending along the extrahepatic bile duct, and the upstream bile ducts were dilated. We performed extrahepatic bile duct resection under a preoperative diagnosis of the extrahepatic bile duct cancer. A histopathological examination of the resected specimen revealed that the tumor consisted of spindle cells which exhibited a palisading arrangement. Immunohistochemical staining was positive for protein S-100 and vimentin. Based on these pathological findings, we diagnosed the patient with schwannoma of the extrahepatic bile duct. Our search of the relevant literature revealed 19 case studies of biliary schwannomas. In our case, the surgical findings showed that the tumor was noninvasive and mobile. During surgery, a fast frozen section analysis was performed, and no malignant findings were observed. These results enabled us to avoid extrahepatic bile duct resection with major hepatectomy. We experienced a case of biliary schwannoma that was difficult to distinguish from bile duct cancer.

Case report of portal hepatic schwannoma: presentation of multimodality images

Background

Portal hepatic schwannoma is a rare benign tumor and difficult to diagnose preoperatively because of its rarity and imaging manifestations that mimic malignancy. We present a case of portal hepatic schwannoma that showed moderate contrast enhancement on computed tomography (CT), extension along the bile duct on T2-weighted imaging and magnetic resonance cholangiopancreatography (MRCP), and uptake of ¹⁸F-fluorodeoxyglucose (FDG) on positron emission tomography.

Case presentation

Ultrasonography at an annual health checkup identified a hepatic mass in a 38-year-old woman. CT showed a well-defined portal hepatic tumor with mild contrast enhancement. T2-weighted imaging and MRCP showed a clavate tumor extending along the intrahepatic bile ducts but no dilatation of the ducts. The tumor exhibited increased FDG uptake, such as maximum standardized uptake values of 5.0 and 6.5 in the early and late phases, respectively. Neither dilatation of intrahepatic bile ducts nor lymphadenopathy was identified, and the multimodality imaging suggested hepatic portal lymphoma, gastrointestinal tumor, or IgG4-related disease rather than cholangiocarcinoma. A needle biopsy via endoscopic ultrasonography was performed, and immunohistology confirmed the tumor as a schwannoma.

Conclusions

The diagnosis of a portal hepatic schwannoma requires immunohistological examinations in addition to multimodality imaging studies to reflect fully the pathohistological characteristics of the tumor.

Successful preoperative diagnosis and minimally invasive surgery of bile duct schwannoma

Bile duct schwannomas are rare benign tumors that frequently mimic more life-threatening tumors. Till date, only a few of these tumors have been diagnosed preoperatively. Herein, we report the case of a 68-year-old man who presented with a 1-day history of epigastralgia. The patient was preoperatively diagnosed with bile duct schwannoma using transpapillary biliary forceps biopsy and underwent local resection without major complications. The findings of our study indicate that endoscopic tumor biopsy may be helpful in diagnosing bile duct schwannoma before surgery; thus, enabling surgeons to plan an appropriate surgery while avoiding overtreatment.

[Primary Hepatic Schwannoma]

A primary benign schwannoma of the liver is extremely rare. Only 30 cases have been reported in the medical literature worldwide, and only one case has been reported in Korea previously. A 56-year-old man was admitted to Gil Medical Center with incidental findings of a hepatic mass by abdominal computed tomography. The computed tomography and magnetic resonance image revealed a 3×2 cm-sized solid mass in the left lobe of the liver. Histological examination confirmed the diagnosis of a benign schwannoma, proven by positive immunoreaction with the neurogenic marker S-100 protein and a negative response to CD34, CD117, and smooth muscle actin. We report a primary benign schwannoma of the liver and review the literature.

Schwannoma of the biliary tract resembling cholangiocarcinoma: A case report and review

Schwannomas are benign tumours derived from Schwann cells and are extremely rare in the biliary tract. We present the case of a 62-year-old patient with a common bile duct schwannoma that resembled a cholangiocarcinoma. We also review all 17 previously published cases of schwannoma of the biliary tract and discuss the challenges of preoperative diagnosis.

Biliary tract schwannoma: A rare cause of obstructive jaundice in a young patient

Schwannoma is a tumor derived from Schwann cells which usually arises in the upper extremities, trunk, head and neck, retroperitoneum, mediastinum, pelvis, and peritoneum. However, it can arise in the gastrointestinal tract, including biliary tract. We present a 24-year-old male patient with obstructive jaundice, whose investigation with computed tomography abdomen showed focal wall thickening in the common hepatic duct, difficult to differentiate with hilar adenocarcinoma. He was diagnosed intraoperatively schwannoma of common bile duct and treated with local resection. The patient recovered well without signs of recurrence of the lesion after 12 mo. We also reviewed the common bile duct schwannoma related in the literature and evaluated the difficulty in pre and intraoperative differential diagnosis with adenocarcinoma hilar. Resection is the treatment of choice for such cases and the tumor did not recur in any of the resected cases.

Primary hepatic benign schwannoma

Schwannoma is predominantly a benign neoplasm of the Schwann cells in the neural sheath of the peripheral nerves. Occurrence of schwannoma in parenchymatous organs, such as liver, is extremely rare. A 64-year-old man without neurofibromatosis was observed to have a space-occupying lesion of 23mm diameter in the liver during follow-up examination for a previously resected gastrointestinal stromal tumor (GIST) in the small intestine. He underwent lateral segmentectomy of the liver under a provisional diagnosis of hepatic metastatic recurrence of the GIST. Histological examination confirmed the diagnosis of a benign schwannoma, confirmed by characteristic pathological findings and positive immunoreactions with the neurogenic marker S-100 protein, but negative for c-kit, or CD34. The tumor was the smallest among the reported cases. When the primary hepatic schwannoma is small in size, preoperative clinical diagnosis is difficult. Therefore, this disease should be listed as differential diagnosis for liver tumor with clinically benign characteristics.

Resection of perihilar biliary schwannoma

INTRODUCTION

Schwannomas are usually benign nerve sheath tumors, which typically arise in the head, neck, spinal cord and extremities. Schwannoma of the biliary tract is an extremely rare finding. Patients generally lack symptoms and seek medical attention when tumor growth causes obstructive jaundice. Preoperative diagnosis is difficult and resection is the treatment of choice.

METHODS

A 54 year-old female with history of back and right labia minor melanoma for which she underwent complete excision and right inguinal lymph node dissection more than 10 years ago, was evaluated for new onset gastroesophageal reflux symptoms and found to have markedly abnormal liver enzymes. Imagining studies revealed intrahepatic ductal dilatation and a 5.2 cm mass in the porta hepatis that was not consistent with cholangiocarcinoma or hepatocellular carcinoma. Multiple percutaneous biopsies of the mass failed to provide a definitive diagnosis. With a high clinical suspicion of metastatic melanoma and no other evident sites of disease, operative intervention was undertaken for diagnosis and definitive treatment.

RESULTS

Diagnostic laparoscopy was performed initially, but access to the mass was difficult, given its location. Subsequently, the patient underwent laparotomy, with tumor excision, common bile duct resection and hepato-jejunostomy. Pathologic examination and analysis were consistent with cellular schwannoma. Postoperatively, the patient recovered uneventfully, and liver function studies returned to normal.

CONCLUSION

Schwannomas are uncommon tumors, which very rarely arise from the biliary tract and cause biliary obstruction. Exploration is indicated in order to establish the diagnosis and to render definitive treatment.