Imaging-guided core biopsy for the diagnosis of malignant tumors in pediatric patients

OBJECTIVE. We evaluated the ability of imaging-guided core biopsy to obtain sufficient tissue from pediatric tumors for a definitive diagnosis of mali gnancy on which treatment could be based. MATERIALS AND METHODS. Thirty-four biopsies (biopsies of the abdomen, 32; o f the chest, 2) were performed on 34 children at presentation under CT or s onographic guidance using 14-, 18-, or both 14- and 18-gauge needles. A min imum of two tissue cores was obtained. Most biopsies were performed under g eneral anesthesia, permitting other procedures to be performed. The biopsy results were confirmed by subsequent surgical pathology, bone marrow biopsy , biochemical or clinical features, and follow-up examination. RESULTS. The needle biopsy diagnoses were nephroblastoma (n = 11), neurobla stoma (n = 7), renal cell carcinoma (n = 2), synovial sarcoma (n = 1), non- Hodgkin's lymphoma (n = 2), clear cell sarcoma (n = 1), rhabdoid tumor (n = 1), pulmonary blastoma (n = 2), embryonal rhabdomyosarcoma (n = 1), germ c ell tumor (n = 1), adrenal carcinoma (n = I), inflammatory tissue (n = 2), desmoplastic tumor of the mesentery (n = 1), and primitive neuroectodermal tumor (n = 1). In 28 patients, the results were confirmed as correct (22 wi th surgery and 6 with follow-up examination). Four patients required additi onal biopsy. In two of these patients, the core biopsy showed inflammatory tissue only, and an open biopsy of a different site was performed; the othe r two patients did not respond to therapy on the basis of needle biopsy res ults, and an open biopsy altered the diagnosis. Two patients with widesprea d disease were excluded because they did not respond to treatment and were too ill to undergo an open biopsy. Only one significant complication was re corded. CONCLUSION. Imaging-guided core biopsy is a safe and reliable means of obta ining sufficient tissue to make a confident histologic diagnosis of maligna nt pediatric tumors in a high percentage of patients.