Although perilymphatic pulmonary nodules can also be perifissural in distribution, they should be distinguished from PFNs, as they are usually associated with a number of conditions.
PFNs are typically seen as well-circumscribed, smoothly marginated homogeneous nodules in contact with or closely related to a pulmonary fissure. Most show a triangular, oval/lentiform, rectangular, or dumbbell shape. They may often show a septal attachment to the pleural surface 3.
Worrisome features that are not typical for lymph nodes and should be reported, prompting for imaging follow-up, include 6:
- round morphology or contour irregularity
- the adjacent fissure is abnormal: bowed, retracted, or transgressed
Treatment and prognosis
If they have typical morphology they are favored to be benign despite some nodules having a tendency to grow over serial scans 2.
- 1. Ahn MI, Gleeson TG, Chan IH et-al. Perifissural nodules seen at CT screening for lung cancer. Radiology. 2010;254 (3): 949-56. Radiology (full text) - doi:10.1148/radiol.09090031 - Pubmed citation
- 2. de Hoop B, van Ginneken B, Gietema H et-al. Pulmonary perifissural nodules on CT scans: rapid growth is not a predictor of malignancy. Radiology. 2012;265 (2): 611-6. doi:10.1148/radiol.12112351 - Pubmed citation
- 3. Frank L, Quint LE. Chest CT incidentalomas: thyroid lesions, enlarged mediastinal lymph nodes, and lung nodules. Cancer Imaging. 2012;12 (1): 41-8. doi:10.1102/1470-7330.2012.0006 - Free text at pubmed - Pubmed citation
- 4. Mets OM, Chung K, Scholten ET, Veldhuis WB, Prokop M, van Ginneken B, Schaefer-Prokop CM, de Jong PA. Incidental perifissural nodules on routine chest computed tomography: lung cancer or not?. (2018) European radiology. 28 (3): 1095-1101. doi:10.1007/s00330-017-5055-x - Pubmed
- 5. Snoeckx A, Reyntiens P, Desbuquoit D, Spinhoven MJ, Van Schil PE, van Meerbeeck JP, Parizel PM. Evaluation of the solitary pulmonary nodule: size matters, but do not ignore the power of morphology. (2018) Insights into imaging. 9 (1): 73-86. doi:10.1007/s13244-017-0581-2 - Pubmed
- 6. Bueno J, Landeras L, Chung JH. Updated Fleischner Society Guidelines for Managing Incidental Pulmonary Nodules: Common Questions and Challenging Scenarios. (2018) Radiographics : a review publication of the Radiological Society of North America, Inc. 38 (5): 1337-1350. doi:10.1148/rg.2018180017 - Pubmed