Here's what they said:

1. "When I was in EMS training, we had to do [medical examiner] rotations to learn gross anatomy. The ME told us of a case they had the previous month where they had an unattended death in a rental property of a single fortysomething person with no known medical history. The autopsy was unremarkable until the labs came back: carbon monoxide poisoning."

"Turned out his heating system had a weird malfunction that would emit massive amounts of CO. In this case the autopsy saved someone else's life as the heating system was fixed to avoid it from potentialy killing the next renter."

—u/i_am_voldermort

2.

"Back in gross anatomy, I was cutting into my guy's butt. This guy had so much fat. If you didn't know fat is yellow. I finally separate the sea of yellow from his red muscles and as I'm parting his muscles, I see more yellow deep in his gluteus maximus. I'm thinking wtf is this. How the fuck does this guy have fat under his muscles? I pull it out and it ended up being a massive lipoma. Could easily fill a C cup, but don't think that's why he died. His lungs were pretty fucked up so I think he was a smoker."

—u/Definitlynotmartin

3. "Once, I sent a cow for autopsy after it died suddenly. The report came back that there was a wire in its heart (not hugely uncommon; they work through from the digestive tract), but also this cow had a deflated football in its stomach, which had been there for some time and did not appear to hinder digestion."

4. "We had this guy who had some heart issues, came to the hospital with some heart failure symptoms, got progressively worse and worse, and then just couldn't go anymore. This guy had extensive imaging, testing, the whole deal. Well, when we were doing the organs, everything looked fairly okay, even the heart didn't look THAT bad for the picture they gave us."

"Then, I slice open the liver (which was admittedly a bit larger than normal), and boom, it was about 80% replaced by a nasty, nasty abscess. I'm talking liters of pus. He didn't have a fever and they didn't see anything on imaging, clinical, or even blood cultures. We were never sure if the heart issues maybe worsened before he got to become septic, but that is still the largest liver abscess I've seen in my life."

—u/alksreddit

5. "A lady with cirrhosis died and when she arrived, she had a [swollen] belly. We assumed it was [fluid buildup in her liver due] to her cirrhosis, but when we opened her abdomen this thick, clear, gelatinous mucus poured out. We measured it at over two liters of this sticky gel. Turns out she had an undiagnosed mucinous tumor on her ovary, which had spread all throughout her abdomen."

—u/Nice_Dude

6. "When I was in my intro to EMS class, my teacher brought in a death investigator and former autopsy examiner to speak to our class. She told us while she worked as an autopsy examiner, she got this woman who, at the time, mysteriously suffocated after a car accident. Apparently, while she was driving, she grabbed her lighter from her purse and was holding it in her mouth while she fumbled through her bag for her cigarettes. While doing this, she got T-boned."

7. "As a student in my dental school gross anatomy lab, we were dissecting the throat. Upon entering the larynx, we discovered a tooth the patient had swallowed. The tooth was lodged over the epiglottis, and we [changed] the cause of death to choked on foreign substance."

—u/Present_Easte_1305

8. "I've seen bone cancer that spread to a young person's lung, which basically replaced the whole lung with bone. I had to saw the lung in half with a bone saw to get samples."

—u/Nice_Dude

9. "Undiagnosed widespread metastasized cancer in a college kid that had died in a bar fight gone bad. It's one of the small mysteries of my career thus far that has stuck with me. The primary mystery [is] how it could be that he wouldn't have noticed his condition or sought medical attention prior to his death. This was not some mere colon polyp, it was everywhere."

10. "I mainly deal with perinatal autopsies (stillbirths and neonatal deaths) but one time I did an adult as a favor because the other pathologist on duty was the neighbor of the deceased. The neighbor had a known tumor and declined any investigation into what it was because they thought it would be incurable. Sadly it ended up being a very easily treatable tumor, and a small biopsy would have easily diagnosed it."

—u/k_sheep1

11. "The other day I autopsied a decomposed mid-50s lady with a small plastic container in her rectum filled with a clear liquid. I tried using a urine drug screen card to test it, but it did not work."

—u/Interesting-Common-5

12. "I met a medical examiner at a friend's party recently, and he told us that once he received the body of a cheese factory worker who fell and drowned/burned in molten cheese. It was super awkward as the corpse they received was embedded in a chunk of cheese as it had cooled down. Felt like carving out a corpse from the leftovers of a fondue.

13. And finally, "It’s strange to see the food that the decedent ate. It stops digesting so if they had just eaten shortly before death, you get some interesting stuff. One person had been at a party and ate potato salad but had clearly just kind of gulped it down. Big chunks of unchewed food that you could have put into a container and no one would have even known it was actually consumed already."

—u/makeanameforme

Note: Submissions have been edited for length and/or clarity.