Complex sentence: Lesions can be "transverse", occurring between the rings of the trachea, or "longitudinal" or "spiral", occurring along the membranous part of the trachea, the main bronchi, or both.
Split into simpler sentences: Lesions can be transverse, occurring between the rings of the trachea, longitudinal or spiral. They may occur along the membranous part of the trachea, the main bronchi, or both.