A CASE OF TRAUMATIC NEUROMA OF THE COMMON BILIARY DUCT SIMULATING A CHOLANGIOCARCINOMA

We present a case of traumatic neuroma of the common bile duct in a 53-year-old woman who presented with jaundice,5months after cholecystectomy. Physical examination revealed jaundice, epigastric pain and scratching lesions. Gamma glutamyl transferase (GGT) at 109 U/L, Alkaline phosphatase at 175U/L. CA19-9 was at 500U/mlMagnetic resonance cholangiopancreatography revealed a T1 and T2hyperintense lesion of peri-hilar fat. An increase in intensity was noted after useof gadolinium.Exploratory laparotomy was performed with the presumptive diagnosis of cholangiocarcinoma. Pathologic analysis of the surgical specimen revealed Haphazard mature nerves, consistent with a bile duct neuroma. Follow-up of the patient showed no post-operative complications or signs of recurrence.

Abdominal ultrasonography demonstrated moderately dilated intraand extrahepatic ducts.Magnetic resonance cholangiopancreatography revealed a T1 and T2hyperintense lesion of peri-hilar fat. An increase in intensity was noted after useof gadolinium.
Intrahepatic biliary ducts were discretely dilated with presence of a short stenosis below the biliary confluence extending over 6 mm. (Figure 1) Exploratory laparotomy was performed with the presumptive diagnosis of cholangiocarcinoma. At operation many adhesions were found, a resection of extrahepatic bile duct was performed along with a hepatico-duodenal bypass and lymph node dissection of the hepatic pedicle.
Pathologic analysis of the surgical specimen revealed Haphazard mature nerves within mature collagenous scar. The observed nerves were made of axons and Schwann cell which lacked atypia or mitotic figures.These findings were consistent with a bile duct neuroma. (Figures 2 and 3

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An immunohistochemicalystudy allowed confirmation of the nervous nature of the observed fibers since they were S-100 positive (Figure 4) The postoperative course was uneventful, and the patient was discharged 10 days after surgery. Follow-up of the patient showed no post-operative complications or signs of recurrence.

Discussion:-
Traumatic neuroma of the biliary tree was first described by Husseinoff in 1928. [4] Cholecystectomy is the most frequently performed operation in abdominal surgery [6] Neuromas have been most commonly described after both laparoscopic and open cholecystectomy.
They may also occur with common bile duct exploration procedures. [7] Traumatic nerve cell growth after surgery is thought to be the trigger of Neuroma formation. [4][5][6][7] It is a nonneoplastic disorganized proliferation of axons, Schwann cells, and perineurial cells in a fibrocollagenous stroma. [7] Sympathetic and parasympathetic fibers arising from the greater and lesser splanchnic nerves areinvolved in the pathogenesis. [8] The incidence of traumatic neuroma is unknown since most patients remain asymptomatic.
Most occur in the cystic duct stump after cholecystectomy and are asymptomatic. Rarely they present with intermittent or continuous symptomatic epigastric pain or right upper quadrant and jaundice. Our patient presented with right upper quadrant pain and jaundice.

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Accurate preoperative diagnosis of neuroma can be difficult. Many patients, as in our case, were thought to have an underlying malignancy. [9] In most cases, the cholangiocarcinoma is the leading differential diagnosis because of the similarity of presentation. [9][10][11][12][13][14] Obstructive jaundice is frequently associated with false CA19-9 elevation in benign conditions. Our patient had an elevated CA 19-9 level of 500 U/ml prior to surgery, that is suspected to related to malignancy. [9,10,13] Radiological explorations show dilated common bile duct and extrahepatic bile ducts. They can very rarely identify the traumatic neuroma as a strongly enhanced lesion, as in our case, on MRImaging or CT-scan [1] In the majority of cases, adefinitive diagnosis is obtained by pathological examination of the surgical resection specimen.
In the literature, a neuroma was recently diagnosed preoperatively by biopsy with cholangioscopy. [8] Pathologically, the lesion manifests as haphazard mature nerves within mature collagenous scar. The nerves are made of axons and Schwann cell. No atypia or mitotic activity should be observed.
The main treatment is surgical resection of the lesion. No cases of recurrence have been found in the English literature.

Conclusion:-
Awareness of traumatic neuromas should be the rule especially in front of a patient with a history of biliary tree surgery. This may aid preoperative work up and planning, as well as patientcounseling.