Minimally invasive biopsy in retroperitoneal tumors.

Minimally invasive biopsy procedures have proven over the years to be essential for obtaining a correct diagnosis of retroperitoneal tumors, that allows proper therapeutical conduct. These procedures offer valuable tissue fragments for histopathological examination, that permits the distinction between benign and malignant tumors, identifying the tumors that can benefit from neo-adjuvant treatments, such as chemotherapy or radiotherapy and those that have a direct surgical indication. We have searched the existing data regarding minimally invasive biopsy in retroperitoneal tumors using the PubMed database, in order to evaluate the role of this procedure in establishing a correct diagnosis, as well as to find out the risks of tumor cell seeding and local recurrence after needle biopsy. The risk of tumor cell seeding is very low (<2%) and in some cases, it is considered negligible (<0.5%). Compared to open biopsy, needle biopsy seems to be associated with a significantly lower risk of tumor cell seeding. According to the existing data, the incidence of needle track tumor cell seeding also depends on the histological type of the tumors. Image-guided retroperitoneal biopsy has proven to be low cost, accessible, and a reliable procedure (in terms of diagnostic accuracy), usually associating with a low rate of complications and a low risk of tumor seeding. Several authors have underlined the importance of the retroperitoneal approach and the association with a co-axial imaging technique in order to avoid potentially deadly complications.