Inflammatory myofibroblastic tumour of the common bile duct: a case report and literature review

INTRODUCTION: Inflammatory myofibroblastic tumour (IMT) of the common bile duct (CBD) is an extremely rare low-grade malignancy with various biological behaviours and a lack of specific clinical and histopathological features. Preoperative and intraoperative diagnosis are challenging, and a diagnostic delay may increase surgical complexity. CASE PRESENTATION: We present the case of a 34-year-old male with no relevant medical history who presented with jaundice of 20 days of evolution. Histology and immunohistochemistry confirmed the diagnosis of an IMT with anaplastic lymphoma kinase (ALK)-1 expression. In addition, a review of the relevant literature revealed 13 published reports of biliary IMTs. The clinical history and histopathological features in these 13 cases were compared with those in our case to provide a comprehensive overview of the clinical manifestations and histopathological features of the disease. CONCLUSION: IMT of the CBD is an extremely rare low-grade malignancy that mainly occurs in middle-aged female patients. The main clinical manifestation is monosymptomatic jaundice. The reported tumours originated in the middle and lower segments of the CBD, with an average size of approximately 3.5 cm × 3.0 cm and tumour cells expressing smooth muscle actin (SMA), vimentin and ALK. Abnormal ALK expression and ALK gene rearrangement represent potential histopathological and differential diagnoses. A clear diagnosis by preoperative biopsy and intraoperative frozen section examination is critical and can significantly reduce surgical trauma. The prognosis is good, and very few patients experience recurrence or distant metastasis.