2.1 Patients
This was an institutional review board approved retrospective analysis of ultrasound guided PCNB performed in the Surgical Oncology Department at Beijing Children’s Hospital from August 1st 2012 to January 31st 2019. Those whose PCNB pathology indicates non-surgical treatment such as inoperable malignant diseases (of which lymphoma comprised a large portion) and certain benign conditions were excluded. Those who chose to be treated elsewhere were also excluded as their final surgical pathologies were not traceable or obtained. Only patients whose PCNB reports indicating operations and received surgery in our department were included. Medical records were reviewed for patient demographics, the anatomical location of the tumor biopsy specimen, the method of tumor biopsy, pathology, and complications. Unfortunately, the number of cores taken for core needle biopsies and the gauge of needles were not always recorded. Therefore, we did not take the two variables into analysis in this study. Final surgical pathological diagnoses were used as the gold standard to assess the diagnostic efficiency of PCNB. The PCNB pathology and surgical pathology were analyzed for diagnostic test statistics. The flowchart of patient selection is shown in Fig. 1.