When Poe died, he was buried, rather unceremoniously, in an unmarked grave in a Baltimore graveyard. Twenty-six years later, a statue was erected, honoring Poe, near the graveyard’s entrance. Poe’s coffin was dug up, and his remains exhumed, in order to be moved to the new place of honor. But more than two decades of buried decay had not been kind to Poe’s coffin—or the corpse within it—and the apparatus fell apart as workers tried to move it from one part of the graveyard to another. Little remained of Poe’s body, but one worker did remark on a strange feature of Poe’s skull: a mass rolling around inside. Newspapers of the day claimed that the clump was Poe’s brain, shriveled yet intact after almost three decades in the ground.I don't believe a brain tumor or any other body tissue would calcify after death (unless there were some unusual mineralogical conditions in the soil), but some neoplasms such as meningiomas and various metastases do calcify during life. Interesting.
We know, today, that the mass could not be Poe’s brain, which is one of the first parts of the body to rot after death. But Matthew Pearl, an American author who wrote a novel about Poe’s death, was nonetheless intrigued by this clump. He contacted a forensic pathologist, who told him that while the clump couldn’t be a brain, it could be a brain tumor, which can calcify after death into hard masses.
Addendum 2021: I just finished reading Hervey Allen's Israfel: The Life and times of Edgar Allan Poe - an immensely detailed biography of Poe. Poe is often described in the terminology of the mid-nineteenth century as experiencing "brain fever,",which may be delirium associated with alcohol, but he is also noted by some observers to have some facial asymmetry.