I recently had an operation to have a small tumor removed. The hospital pathology
Lab report said it was benign, but I want to get a second opinion from a different, independent pathology facility.

I am having trouble getting the slides from them-- they say they have to review them to
See which ones they will give me (they made 17). But the lab I want to send them to says
That they should get all 17. The rationale is that if some of the slides were determined to
Show a malignancy, they would only need those, to confirm or refute. But since the overall
Result was that there was no malignant cells, they want to confirm or refute that on all
Possible slides.

Questions: Whose property are the slides-- (they contain part of my body)? Does the hospital have an obligation to give me all of the slides, to facilitate a second opinion?
What are my options if they refuse to do so>

The slides are the property of the lab in which they are located. The hospital has the obligation of giving you all of the slides if you sign for them to be turned over to another lab.