Sentence:  Microscopic studies of the gastrocnemius , pectoralis major , transversus abdominis , biceps brachii , and diaphragm showed atrophy as well as varying degrees of injury ranging from <WSD>swelling</WSD> and vacuolization to focal necrosis of the muscle fibers . 
Meaning of the word marked with <WSD> tags:  an abnormal protuberance or localized enlargement