Second Opinion from Johns Hopkins -- delayed (?)

After being diagnosed with PCa three weeks ago at Sloan Kettering in NYC, I quickly requested that my slides be sent out to Johns Hopkins/Epstein for a second opinion. As of yesterday, Sloan Kettering still hadn't received the results, so I contacted Johns Hopkins directly.

The intern at Johns Hopkins told me that evaluation had hit a delay because after reviewing the slides, they have decided to request the original "blocks" from Sloan Kettering. They are having trouble evaluating the slides because of the small percentage/linear amount of cancer. They want to apply dye to the original "blocks." The blocks should now be en route to Johns Hopkins.

Just wondering if anyone else here has experienced something like this when requesting an evaluation of biopsy slides? Is this type of delay common?

I was listening and trying to write furiously when talking to the intern, so I hope I transcribed the facts correctly.