SIGNIFICANCE OF PERCUTANEOUS NEEDLE-BIOPSY IN PATIENTS WITH MULTIPLE PULMONARY NODULES AND A SINGLE KNOWN PRIMARY MALIGNANCY

Objective: To determine the necessity of percutaneous lung biopsy in p atients with a single known primary malignancy and multiple pulmonary nodules. Design: Retrospective study. Setting: Tertiary care universit y hospital. Results: We reviewed all percutaneous lung biopsy specimen s over a 6-year period. One hundred forty-six patients with a single k nown primary malignancy and multiple pulmonary nodules had biopsies pe rformed up to 19 years following diagnosis of the primary neoplasm. On e hundred thirty-seven biopsy specimens (93.8%) were positive for meta stases. Eight patients (5.5%) had a nondiagnostic biopsy specimen; how ever, subsequent imaging studies and the clinical course strongly sugg ested diffuse metastatic disease. One patient (<1%) with breast carcin oma developed nodules 3 years after initial diagnosis and had resoluti on without a definitive diagnosis or therapy. Conclusion: Patients wit h a single known primary malignancy and multiple pulmonary nodules who present for percutaneous needle biopsy will have pulmonary metastases in the vast majority of cases. Biopsy in these patients rarely change s the clinical course as other diagnoses are rarely established.