Diagnostic yield and safety of percutaneous CT-guided biopsy of retroperitoneal lesions and analysis of imaging features

Background Computed tomography (CT)-guided biopsy is emerging as a preferred method for obtaining tissue samples from retroperitoneal lesions due to clear visualization of needle and vessels. Purpose To assess diagnostic yield and safety of CT-guided biopsy of retroperitoneal lesions and compare CT findings in different disease categories. Material and Methods This retrospective analytical study included 86 patients with retroperitoneal lesions who underwent CT-guided biopsy from December 2010 to March 2020. All procedures were performed with co-axial technique and multiple cores were obtained and subjected to histopathology. Additional tests like immunohistochemistry or microbiological analysis were done depending on clinical suspicion. Diagnostic yield calculation and comparison of imaging findings was done by one-way ANOVA, chi-square, and Fisher's exact tests. Results CT-guided biopsy was technically successful in all cases with a diagnostic yield of 91.9%. Minor complications in the form of small hematomas were seen in two patients. Major disease categories on final diagnosis were lymphoma, tuberculosis, and metastases. A variety of malignant and benign soft-tissue neoplasms were also noted less commonly. With help of immunohistochemistry, lymphoma subtype was established in 88.8% of cases. Addition of microbiological tests like the GeneXpert assay helped in the diagnosis of tuberculosis in some cases. A mass-like appearance and vascular encasement was common in metastatic group and lymphoma. Conclusion Percutaneous CT-guided biopsy is a safe method for the sampling of retroperitoneal lesions with high diagnostic yield. Imaging findings are mostly overlapping; however, some features are more common in a particular disease condition.