Development and management of iatrogenic biloma post microwave ablation of solitary metastatic breast cancer lesion in the liver

Thermal ablation is used to treat liver metastasis including those from breast cancer. The ablation is associated with pain, hemorrhage, and biliary structure damage leading to bilomas. Biloma is a collection of bile that can occur inside or outside the biliary system, which could happen as a rare complication of surgery (from procedures like abdominal surgery or diagnostic procedures), trauma, or spontaneously. We report a case of biloma development after microwave ablation (MWA) of a metastatic lesion in the liver. We present a 66-year-old female diagnosed with stage 4 intraductal carcinoma of the right breast with metastasis to the liver. She developed biloma and infarction of the left lobe of the liver following MWA, which was treated with percutaneous internal/external biliary drain placement. Her symptoms and liver function tests were completely resolved after 3 months, and her left hepatic lobe completely atrophied in the same period. Biloma is a rare but concerning complication of MWA, therefore high suspicion should be maintained in patients presenting with cholestatic symptoms and fever postprocedure. When identified, drainage with antibiotic therapy can effectively treat biloma and resolve the symptoms.