Purpose: This study analyzed the clinical characteristics, diagnostic evaluation, prevalence of malignancy, and outcome of patients with a solitary pulmonary nodule (SPN) encountered in the outpatient practice of a pulmonologist in an urban university hospital from 1990 to 1993.
Patients and methods: SPN was defined as a round or ovoid density < or = 3 cm in diameter within the lung parenchyma. Patients with and without lung cancer in SPNs were compared.
Results: Forty patients had a mean age of 65 years, an almost equal sex distribution, high prevalences of cardiovascular disease (53%) and chronic obstructive pulmonary disease (COPD) (33%), but a low incidence of tuberculosis. The mean size of SPNs was 1.8 cm. The prevalence of malignancy was 53%. In SPNs < or = 2 cm in diameter, the prevalence of malignancy was 43%. Nonsurgical biopsy techniques made a diagnosis in 78% of patients. In 94% of patients with lung cancer in SPNs, the tumor was resectable (stage 1, 2, or 3A), emphasizing the need for early detection. Despite the small size of the SPNs, the prevalence of malignancy was high.
Conclusion: Despite the advanced age and high prevalence of cardiovascular disease and COPD in patients with SPNs, lung cancer that occurs in these lesions appears to have a favorable prognosis if detected promptly.