Traumatic Neuroma Arising from Surgical Trauma during Conversion from Laparoscopic to Open Cholecystectomy

Traumatic neuroma is an abnormal proliferation of injured nerves resulting from trauma or surgery. We present a case of traumatic neuroma arising in the cystic duct after cholecystectomy. A 66-year-old man was referred to our department due to a biliary tumor. He had undergone cholecystectomy 20 years prior. Cholangioscopy showed an elevated lesion covered with smooth mucosa. Histological examination revealed normal bile duct mucosa. Although benign disease was suspected, the possibilities of malignant disease could not be excluded. Extrahepatic bile duct resection was planned to include intraoperative rapid-freezing of a biopsy specimen followed by histopathological examination. These intraoperative histology results showed proliferation of nerve and fibrous tissue only, resulting in the diagnosis of traumatic neuroma, so no lymph nodes were removed. To avoid excessive surgical intervention, histopathological examination of an intraoperative rapid-frozen biopsy specimen may be important for diagnosing traumatic neuroma.