Any idea what’s happening with this tomato?

Hi all. Hope someone can shed a little light on this tomato fruit I found today. There was one other like it. This plant has many other healthy fruit on it, but I’m wondering if I should be concerned. It’s on the side, not the stem or blossom end. The tomato doesn’t stink or feel weird, and the bad patch is almost leathery.

My hypothesis is damage of some kind that the plant managed to heal.

Thanks!
Daniel

Sunburn?

That looks like typical blossom end rot to me.

Edited.
ps- I'm wrong.

That's anthracnose. It's caused by a fungus, and likes hot, humid conditions. I've found it more problematic in my gardens when tomato plants are planted too close together which limits air flow through the plants. Tomato plants transpire a lot of water and good air flow from breezes can really help keep things from getting too moist.

James's, right!!!  I read the message too quickly and thought Daniel said that the fruit pictured was on its side. I now see that he meant that the lesion was on the side of the tomato.

Yes, that's anthracnose. It can look a bit different from tomato to tomato. But I'm gonna agree with James. It's anthracnose.

While sunburn is a good guess too, I'm going to venture to say it's not that due to coloration on the lesion. The sunburn I've  seen on my tomatoes is straw blond without dark markings.

As you can see, it's sometimes difficult to diagnose a problem just from a photo. It's much easier and more accurate when you can stand there and evaluate the situation firsthand.

Anthracnose..... new to me, but that sounds like a great diagnosis.

So, should I just thin the plant? We were gone for a bit, and they have gone a bit wild. I hope I don’t need to pull it out.

It has been hot and humid here in eastern PA.

Thanks again, everyone.
Daniel