Carcinoma in Situ vs. CIN3

Hi Everyone-

I know the CIN3 & CIS discussion (are they the same, are they different, etc...) is a common one, but I would really love some opinions/thoughts on my pre and post-operative results.

I am a 22 y/o female and just had my pap smear come back abnormal. In July 2016, my pap came back totally clean/normal. Not even 12 months later (May 2017.. we had a change in insurance so I was able to go back before the full year was up, this was more convenient for me since I was moving out of town), my pap came back abnormal. I was brought into the office and told that my pap came back showing HGSIL CIN2/CIN3 and carcinoma in situ. Literally found this out 48 hours before I was due to move and start a new job..... how lucky.

My doctor was dumbfounded, especially since my pap had come back clean 10 months prior, and I'd only had one encounter between then and now (it only takes one, right?). This thing that was supposed to be "slow-growing" had developed within 10 months... again, how lucky.

My leep conization was scheduled for the next morning. The procedure itself went well, and my recovery was easy. The week between the procedure and my follow-up appointment was what felt like the longest week of my life (i'm sure you all understand that feeling...).

Thankfully, the path report came back showing good news. My margins were clear, and apparently I had been at CIN3 rather than carcinoma in situ. I left feeling confident, but it didn't take long for confusion to set in. Which leads to my next questions....

 

How could a pap come back with more "advanced" results than what's actually there? Aren't false positives much more rare than false negatives?

Why am I reading some places that CIS and CIN3 are the same?

Was this thing cancerous or not?

 

I know they say the #1 thing you're NOT supposed to do after receiving bad news about your health is go online, but I couldn't resist... Now i just feel confused.