I recently found this article which shows an externally-healed lung donation before transplant. The left image is supposedly the lung pre-treatment, and right is post.
In both of these images, black spots can be seen over the lung. However, in the article, they mention that the lung was nearly fully recovered. I have seen other images like this in journals and other media reports -- notably, this viral report that covered a young man's pneumothorax story, but I have never read an explanation as to what black spotting signifies.
Are black spots like this a normal / common benign variance among individuals (similar to freckles on the skin)? Or does it usually signify some type of pathology (ischemia or hemorrhage or anthracosis/tar)?