Significance of biopsy with ERCP for diagnosis of bile duct invasion of DLBCL

Obstructive jaundice is an initial symptom in 1–2% of diffuse large B cell lymphoma (DLBCL) cases. The major cause of bile duct obstruction in patients with DLBCL is extrinsic compression by enlarged lymph nodes. In such cases, the existence of bile duct invasion of lymphoma is rarely mentioned or observed pathologically, so the ratio of bile duct invasion to the total cases of obstructive jaundice, and its significance remains unknown. We report two cases of DLBCL presenting as an obstructive jaundice, in which we demonstrated bile duct invasion pathologically by biopsy from the wall of common bile duct with endoscopic retrograde cholangiopancreatography (ERCP). Endoscopic stent placement is a minimally invasive procedure to relieve cholestasis and is effective for diagnosing bile duct invasion. This procedure should thus be performed in all cases of obstructive jaundice caused by lymphoma to evaluate for bile duct invasion. Our cases suggest that ERCP may be useful as a diagnostic procedure for bile duct invasion.