Presentation
Colon cancer to role out metastasis.
Patient Data
Triangular shape perifissural nodule, typically benign.
Case Discussion
Perifissural nodules (PFNs) are typically seen as well-circumscribed, smoothly marginated nodules in contact with or closely related to a pulmonary fissure. Most show a triangular, oval, round, rectangular, or dumbbell shape. These are benign, with no follow up required. Atypical PFNs are those that meet all the features of a typical PFN but are not attached to a fissure, or attached to a fissure attached with a convex border on one side and rounded on the other. All other fissure attached nodules with a shape that appears not influenced by the fissure are defined as non-PFNs.