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Original Research

Pulmonary Perifissural Nodules on CT Scans: Rapid Growth Is Not a Predictor of Malignancy

Published Online:Nov 1 2012https://doi.org/10.1148/radiol.12112351

Abstract

Perifissural nodules (PFNs) are almost certainly benign and likely represent lymph nodes when observed on a CT scan; rapid growth of PFNs, as seen in 8.3% (66 of 794) of cases, was not a predictor of malignancy.

Purpose

To assess the prevalence, natural course, and malignancy rate of perifissural nodules (PFNs) in smokers participating in a lung cancer screening trial.

Materials and Methods

As part of the ethics-committee approved Dutch-Belgian Randomised Lung Cancer Multi-Slice Screening Trial (NELSON), computed tomography (CT) was used to screen 2994 current or former heavy smokers, aged 50–74 years, for lung cancer. CT was repeated after 1 and 3 years, with additional follow-up CT scans if necessary. All baseline CT scans were screened for nodules. Nodule volume was determined with automated volumetric analysis. Homogeneous solid nodules, attached to a fissure with a lentiform or triangular shape, were classified as PFNs. Nodules were considered benign if they did not grow during the total follow-up period or were proved to be benign in a follow-up by a pulmonologist. Prevalence, growth, and malignancy rate of PFNs were assessed.

Results

At baseline screening, 4026 nodules were detected in 1729 participants, and 19.7% (794 of 4026) of the nodules were classified as PFNs. The mean size of the PFNs was 4.4 mm (range: 2.8–10.6 mm) and the mean volume was 43 mm3 (range: 13–405 mm3). None of the PFNs were found to be malignant during follow-up. Between baseline and the first follow-up CT scan, 15.5% (123 of 794) were found to have grown, and 8.3% (66 of 794) had a volume doubling time of less than 400 days. One PFN was resected and proved to be a lymph node.

Conclusion

PFNs are frequently found at CT scans for lung cancer. They can show growth rates in the range of malignant nodules, but none of the PFNs in the present study turned out to be malignant. Recognition of PFNs can reduce the number of follow-up examinations required for the workup of suspicious nodules.

© RSNA, 2012

References

  • 1 Diederich S, Thomas M, Semik M, et al.. Screening for early lung cancer with low-dose spiral computed tomography: results of annual follow-up examinations in asymptomatic smokers. Eur Radiol 2004;14(4):691–702.
    MedlineGoogle Scholar
  • 2 Henschke CI, Yankelevitz DF, Mirtcheva R, et al.. CT screening for lung cancer: frequency and significance of part-solid and nonsolid nodules. AJR Am J Roentgenol 2002;178(5):1053–1057.
    MedlineGoogle Scholar
  • 3 Swensen SJ, Jett JR, Hartman TE, et al.. Lung cancer screening with CT: Mayo Clinic experience. Radiology 2003;226(3):756–761.
    Google Scholar
  • 4 National Lung Screening Trial Research Team, Aberle DRAdams AMet al.. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med 2011;365(5):395–409.
    MedlineGoogle Scholar
  • 5 Ahn MI, Gleeson TG, Chan IH, et al.. Perifissural nodules seen at CT screening for lung cancer. Radiology 2010;254(3):949–956.
    Google Scholar
  • 6 Xu DM, van der Zaag-Loonen HJ, Oudkerk M, et al.. Smooth or attached solid indeterminate nodules detected at baseline CT screening in the NELSON study: cancer risk during 1 year of follow-up. Radiology 2009;250(1):264–272.
    Google Scholar
  • 7 Matsuki M, Noma S, Kuroda Y, Oida K, Shindo T, Kobashi Y. Thin-section CT features of intrapulmonary lymph nodes. J Comput Assist Tomogr 2001;25(5):753–756.
    MedlineGoogle Scholar
  • 8 van Iersel CA, de Koning HJ, Draisma G, et al.. Risk-based selection from the general population in a screening trial: selection criteria, recruitment and power for the Dutch-Belgian randomised lung cancer multi-slice CT screening trial (NELSON). Int J Cancer 2007;120(4):868–874.
    MedlineGoogle Scholar
  • 9 Xu DM, Gietema H, de Koning H, et al.. Nodule management protocol of the NELSON randomised lung cancer screening trial. Lung Cancer 2006;54(2):177–184.
    MedlineGoogle Scholar
  • 10 Gietema HA, Schaefer-Prokop CM, Mali WP, Groenewegen G, Prokop M. Pulmonary nodules: Interscan variability of semiautomated volume measurements with multisection CT— influence of inspiration level, nodule size, and segmentation performance. Radiology 2007;245(3):888–894.
    Google Scholar
  • 11 Yokomise H, Mizuno H, Ike O, Wada H, Hitomi S, Itoh H. Importance of intrapulmonary lymph nodes in the differential diagnosis of small pulmonary nodular shadows. Chest 1998;113(3):703–706.
    MedlineGoogle Scholar
  • 12 Bankoff MS, McEniff NJ, Bhadelia RA, Garcia-Moliner M, Daly BD. Prevalence of pathologically proven intrapulmonary lymph nodes and their appearance on CT. AJR Am J Roentgenol 1996;167(3):629–630.
    MedlineGoogle Scholar
  • 13 Miyake H, Yamada Y, Kawagoe T, Hori Y, Mori H, Yokoyama S. Intrapulmonary lymph nodes: CT and pathological features. Clin Radiol 1999;54(10):640–643.
    MedlineGoogle Scholar
  • 14 de Hoop B, Gietema H, van Ginneken B, Zanen P, Groenewegen G, Prokop M. A comparison of six software packages for evaluation of solid lung nodules using semi-automated volumetry: what is the minimum increase in size to detect growth in repeated CT examinations. Eur Radiol 2009;19(4):800–808.
    MedlineGoogle Scholar
  • 15 van Klaveren RJ, Oudkerk M, Prokop M, et al.. Management of lung nodules detected by volume CT scanning. N Engl J Med 2009;361(23):2221–2229.
    MedlineGoogle Scholar
  • 16 Hasegawa M, Sone S, Takashima S, et al.. Growth rate of small lung cancers detected on mass CT screening. Br J Radiol 2000;73(876):1252–1259.
    MedlineGoogle Scholar

Article History

Received November 5, 2011; revision requested January 11, 2012; revision received March 13; accepted May 1; final version accepted May 18.
Published online: Nov 2012
Published in print: Nov 2012