This is a typical appearance of this problem. At the top right, you can see a white line, near the 'X', which is an incision from previous surgery. It had recurred in the skin and had these purple, grape-like lesions and this is hemorrhage and bullae formation in the skin associated with this lymphatic malformation.
This was excised down to the chest wall. In fact, you can see in the bottom right picture, the margins of the chest wall musculature. He was grafted with a stent dressing but you can see at the left, a very nice outcome posteriorly, but anteriorly, along the costal margin, there is another recurrence. It may be that the lymphatics track along the intercostal margin into his chest. Even though the MRI didn't show it, I feel he has residual intercostal disease. To remove this would require chest wall resection including the rib. It's really discouraging to remove that much tissue and still end up with a recurrence.