If the skin can keep up in growth rate, it may never open. Others as you have observed will pop early on.

My previous dog started with lipomas at 5 yrs, then came a couple of small cysts at 8 yrs that lasted to the end of her life, a Hemangiopericytoma, and a couple of months after that Lymphoma at age 10 yrs. Also a non-malignant fibroma occured during the last year of her life.

The Hemangiopericytoma was the hardest to detect, as it had the consistency expected for a cyst, but was not very large. The detection method was needle aspirate.