Size of tumour as a risk factor for malignancy in patients with peripheral pulmonary nodules

Peripheral pulmonary tumours are often quite difficult to diagnose and treat. Their detection brings immediately the problem of whether clinicians should just wait and observe or operate the patients. The aim of this study was to determine if there is a direct correlation between tumour size and the risk for malignancy and whether the tumor size should be considered a risk factor for malignancy.

Between 1997 and 2009, 145 patients with peripheral pulmonary tumours of less than 3 cm in diameter underwent video-assisted thoracoscopic (VATS) resection for the purpose of histologic examination of the tumor.

The mean age of the patients was 62.60 +/- 0.95 years. The youngest patient was 17 years old and the oldest--82. The study sample included 61 women and 84 men; the men were statistically significantly more than the women (57.3% and 42.07%, respectively) (t = 2.74, P < 0.01). The total number of patients we operated were 145 with 198 resected tumours. The diameter of the lesions ranged between 0.30 cm and 3 cm (mean 1.41 +/- 0.06 cm). We found that 108 (54.55%) of the tumours were malignant, and 90 (45.45%) were benign, the difference between them failing to reach statistical significance (t = 1.82, P > 0.05). The mean size of malignant lesions was statistically significantly greater than that of benign tumours (1.62 +/- 0.08 cm vs 1.15 +/- 0.06 cm).

The results of this study suggest that the bigger the diameter of the nodule, the greater the percentage share of malignant tumours, which means that the size of the tumour is an important risk factor for malignancy.