Does seeding of the needle tract occur during routine tumor biopsy?
Case reports of tumor spread along the needle tract as a result of percutaneous biopsy are described in the medical literature. Overall, seeding the needle tract is uncommon and the reported rates vary according to organ biopsied. For masses suspected to be hepatocellular carcinoma (HCC), needle track seeding can be a potentially devastating complication in transplant candidates in whom immunosuppression may predispose to seeded tumor growth; however, the American Association for the Study of Liver Diseases believes the risk has been overstated in earlier literature. Needle gauge sizes, number of needle passes, and coaxial versus single-needle systems are believed to influence the risk of tumor seeding, but robust evidence is still lacking. Although this potential complication should be discussed with the patient prior to the procedure, it should not be considered a contraindication to FNA or core biopsy in patients in whom the diagnosis is in question and when knowledge of a specific diagnosis is likely to alter clinical management.
Cystic lesions like suspected cystadenomas or cystadenocarcinomas of the ovary or pancreas should not be sampled percutaneously, even with small, skinny needles. This is associated with a significant risk of postprocedure needle-tract seeding and subsequent pseudomyxoma peritonei or peritoneal carcinomatosis.