Percutaneous biopsy of pediatric solid tumors.

Background: The objective of the current study was to determine the diagnostic accuracy of percutaneous biopsy of pediatric solid tumors, a procedure that is less invasive than open biopsy.

Methods: The authors conducted a retrospective analysis of clinical data related to 202 percutaneous core-needle biopsies of solid tumors at St. Jude Children's Research Hospital over 5.5 years (from 1997 to 2003). In 103 patients, the procedure was performed to establish an initial diagnosis of a suspected malignancy; and, in 99 patients, disease recurrence was suspected. Biopsies were guided by ultrasound, computed tomography, or fluoroscopic imaging. From each tumor, 1-17 core biopsy samples (median, 6 samples) were obtained; the median needle size was 15 gauge (range, 13-20 gauge). The specimens were submitted for histopathologic analysis and other ancillary procedures (molecular pathology and/or cytogenetic analyses). The accuracy of the diagnoses from the biopsies was determined by subsequent surgery with or without pathologic assessment or by outcome.

Results: When the biopsy samples were assessed for the presence of malignancy, there were 121 true-positive results (90% sensitivity), 67 true-negative results (100% specificity), and 14 false-negative results (93% accuracy). In 103 tumors, when the procedure was performed for initial diagnosis, percutaneous needle biopsy showed a sensitivity of 97%, a specificity of 100%, and an accuracy of 98%. The 99 procedures for suspected recurrence were less reliable (sensitivity, 83%; specificity, 100%; accuracy, 88%).

Conclusions: Image-guided percutaneous biopsy was highly accurate and safe in the diagnosis of pediatric malignant solid tumors. This technique may be able to supplant diagnostic open biopsy.