That happens with many types of pears when allowed to ripen on the tree- unless it's the result of codling moth, in which case the seeds would be eaten and you could see a tunnel.

Many varieties of pears need to be picked when still hard, stored for a couple weeks in the fridge and then ripened at room temp for about a week to soften. Otherwise they rot in the center by the time the outside is perfect or sometimes the flesh is very grainy.

Thanks! I didn't know that about pears. We get very strong winds here sometimes and more than half the pears fell off the tree. Could we have collected them and put them in the frig? Marg

if they are sweet and hard. If they are still bitter they don't seem to improve a lot in my experience.