According to a medical report, the soldiers use their rifles to repeatedly slap the left side of their chests – which stimulates hormones on that side of the body. As a result, breasts start to grow only on their left side.

Read more: http://www.foxnews.com/health/2013/0...#ixzz2JL8pAb00
Bull shit. It's a bruise. Maybe a callous.