Try asking the person who set it up if you cannot follow this.

This may be a bit difficult to explain but I'll have a go. Depending on how you have the system set, you will have a test definition set up for Histology. It may be that each sample type has it's own test or you may just have a generic test for a Histology sample. The boxes that pop up asking for second, third samples will be produced by the rules that are attached. You need to alter the rule attrubutes
To find the rules.......
In Admin section, go to Request config the configure tests. Select the test you want to alter then click test rules. This will show you what rules are attached to this test.
To change the rule attributes.........
Go back to Requesting config and select administer rules. Select the rule that asks for the second sample.
On the right hand side of the page, you'll see the rule attributes it will say:
Yes text - in here you type what you want the button to say (e.g. "Yes")
No Text - in here you type what you want the button to say (e.g. "No")
Yes action - in here you can select which further rule you want to play if Yes is selected
No action - in here you choose "no further action" from the drop down.

That should stop the unwanted boxes appearing. Remember though, you have to do this for each and every rule that is attached to the test. If you're still a bit unsure, drop me a line and I'll give you a tinkle
dave.johnson@trafford.nhs.uk