Porta hepatic schwannoma: case report and a 30-year review of the literature yielding 15 cases

Abstract

BackgroundSchwannomas located in the periportal region are extremely rare. Only 14 cases have been reported in the medical literature worldwide. Cases of porta hepatic schwannomas reported in the literature worldwide were reviewed. As a result, it is very challenging for surgeons to make a preoperative diagnosis due to its rarity and nonspecific imaging manifestations.Case PresentationA 57-year-old Chinese female was admitted to our institution with complaint of upper abdominal distension and the abdominal CT in the local hospital revealed a hypodense mass in the porta hepatis. A fine needle aspiration (FNA) was made to confirm the diagnosis, but the result was just suggestive of spindle cell neoplasia. Eventually, the patient underwent surgery and postoperative pathology confirmed schwannoma in porta hepatis. The patient recovered uneventfully with no evidence of recurrence after a follow-up period of 41 months.ConclusionsIt is essential for the final diagnosis of porta hepatic schwannomas to combine histological examination with immunohistochemistry after surgery. The main treatment of porta hepatic schwannomas is complete excision with free margins and no lymph node dissection. In some cases, biliary reconstruction or the proper hepatic and the gastroduodenal artery resection was performed because the tumor was inseparably attached to the extrahepatic bile duct or the proper hepatic and the gastroduodenal artery. Malignant transformation of schwannomas is very rare and the overall prognosis is satisfactory.

Schwannoma in the porta hepatis - laparoscopic excision under laparoscopic ultrasound guidance.

“…Porta hepatic schwannomas are extremely rare, with only 15 cases reported in the literature to date [ 2 ]. They originate from the sympathetic and parasympathetic fibers which are distributed along blood vessels in this localization.…”

“…Macroscopically, schwannomas are spheroidal or ovoid in shape. Larger tumors may undergo secondary degeneration [ 2 , 3 ]. Pathogenesis of both sporadic and genetically acquired schwannomas is associated with defects in the merlin signaling pathways.…”

“…Ultrasound imaging revealed a solid isoechoic or hypoechoic well-bordered mass, computed tomography a heterogeneous mass with peripheral enhancement, MRI a mass with low signal intensity in T1 and high signal intensity in T2-weighted imaging [ 7 , 8 ]. Fine needle aspiration performed preoperatively in 2 patients revealed suspected spindle cell neoplasia or stromal tumor [ 2 ].…”

Multiple schwannomas synchronously occurring in the porta hepatis, liver, and gallbladder

“…[10] In the abdominal cavity, schwannomas are most reported in the retroperitoneum [11] and gastrointestinal tract. [12,13] The occurrence of schwannomas in the porta hepatis, [7] gallbladder, [8] pancreas, [14] or liver [15] is extremely rare. To our knowledge, only 18, 15, and 6 cases of schwannomas involving the liver, [5,6] porta hepatis, and gallbladder, [8] respectively, have been reported.…”

“…[4] Schwannomas occurring in the porta hepatis or abdominal organs are rare. To our knowledge, only 18, 15, and 6 cases of schwannomas have been reported in the liver, [5,6] porta hepatis, [7] and gallbladder, [8] respectively. However, multiple schwannomas synchronously occurring in the porta hepatis and abdominal organs have not been reported so far.…”