“…The minor fissure is concave peripherally but convex centrally, causing the shape of the fissure to resembles an S, hence the name. This sign is highly suggestive of a neoplasm, such as primary lung cancer, but other malignant conditions, such as metastatic lung cancer, malignant lymphoma, mediastinal tumor, or enlarged lymph nodes, may also produce this sign (1)(2)(3)(4).…”