Temporal trends in the prevalence of malignancy in resected solitary pulmonary lesions

Study objective: To determine whether there has been an increase in the prevalence of malignancy among resected, indeterminate solitary pulmonary lesions (SPL) river the past 14 years. Design: A retrospective review of all thoracotomies for indeterminate SPLs from 1981 through 1994. Setting: A university-affiliated VA Medical Center. Patients: Three-hundred seventy resected indeterminate SPLs (all ≤6 cm) in 360 patients. Measurements and results: Virtually all patients were men with an average age of 63±9 years. The average lesion size was 2.5±1.4 cm; 71% were 3 cm or less. Overall, 79% of resected lesions were malignant; 94% of these were bronchogenic carcinomas. Granulomas accounted for more than 50% of benign lesions. The proportion of malignant diagnoses increased from 55 to 60% in 1981 tn 1983 to 90 to 100% in 1990 to 1994 (p<0.005). The increasing proportion of malignancy over time was independent of age at time of operation and lesion size. There was no significant difference in survival among patients with a malignant lesion resected in 1981 to 1983 compared with 1990 to 1994. Conclusion: We conclude that there has been a striking increase in the prevalence of malignancy among resected indeterminate SPLs over the past 14 years in our institution. We suspect that this trend reflects improvements in our ability to diagnose benign SPLs preoperatively, primarily through the use of CT. Our results should prompt other institutions to review their recent experience with the diagnosis of indeterminate SPLs to provide more timely information to physicians and their patients who are contemplating resection of SPLs.