Advertisement Update (post 3, 19): 3/2/16 She molted within the last week. The cyst is still present and looks white, scleritized and about the same size as it has always been. I was able to remove the molt and could examine the intact area of interest. There is a quite small amount of white that may be shed book lung but it is mostly gone as opposed to the other three that shed out normally. Where the book lung should be you see an outline and depression, and there is a thin membrane in the area, with a few red particles near the posterior edge. So maybe the old book lung is being retained, or not developing. But I'm no expert on the shedding of organs in tarantulas.