Autopsies on coronavirus victims are helping doctors understand how the disease affects the body, and a pathologist says one of the most remarkable findings involves blood clots.

Dr. Amy Rapkiewicz, the chairman of the Department of Pathology at NYU Langone Medical Center, published her study at the end of June in The Lancet journal EClinicalMedicine.

Doctors had found clotting in major blood vessels in the early days of the pandemic, but autopsies found the clotting extended into the tiny vessels throughout the body.

“And this was dramatic,” Rapkiewicz told CNN, “because though we might have expected it in the lungs, we found it in almost every organ that we looked at in our autopsy study,” 

The autopsies also showed something unusual about megakaryocytes, which are large bone marrow cells that don’t usually circulate outside the bones and lungs.

“We found them in the heart and the kidneys and the liver and other organs,” Rapkiewicz said. “Notably in the heart, megakaryocytes produce something called platelets that are intimately involved in blood clotting.”

“I could not remember a case before where we saw that,” Rapkiewicz told the Washington Post. “It was remarkable they were in the heart.”

She and other researchers hope to discover how these cells influence small vessel clotting in COVID-19.

Rapkiewicz told CNN that one of the “opportunities — if there is one to count in the virus” is that pathologists have had a chance to examine the organs of many COVID-19 victims and investigate the disease processes, something that really wasn’t available with H1N1 or the original SARS outbreak.