What could it be?

Alright, back in June I collected some N.viridescens larvae and raised them to metamorphosis. Out of 5, 4 morphed. Unfortunately, I was unable to keep these morphs alive, despite my best efforts. I do have to say noto efts really are as hard to raise as people say they can be. Anyway, here is the question I hope I can get answered-

The larva that never morphed just died. This larva in particular had always been runty and never seemed to grow very well, in fact, he wasn't much larger when he died then he was back in August. Before I disposed of him, being curious, I decided to take a look at him under my microscope. Upon looking at him more closely, I noticed this weired triangular-shaped sort of mass inside his throat/upper neck/chest area. Inside the main triangular part something was pulsating, sort of like a heart beat. What could it have been? Is it some sort of parasitic worm? It was so bizarre! Could it have been the larva's heart? He had been dead for at least 8 hours.

Sorry for the barrage of questions, I just found this whole thing a bit fascinating, and I'm curious, especially since the larva had died.

Edit: The larva was previously being fed mosquito larvae and recently was feeding on frozen bloodworm.

Wow sounds weird Dx. You get any pics?

Unfortunately, I don't own one of those new-fangled microscopes that can take photos of your slides/ upload photos to your computer. If it helps any one, I could see the mass to the naked eye, but it wasn't until I used the microscope that I saw the pulsation. This was all on 4X magnification (my microscope isn't all that great.)

I know tumors on dogs and cats sometimes will pulsate on their own, especially when connected to an organ or a muscle mass. (I work as a vet tech) But I am not sure a newt that young could have a tumor. Then again we don't treat exotics so I have no clue.

This might be hard to tell, Nathan. At least I personally do not know any parasites described this way (but someone else might have heard of it).

I guess you do not have any picture (if your microscope doesn't have a camera at least), but can you make some kind of drawing on another larvae-pic? Just to clearly mark the region of the larvae you are talking about. What I read, it could have been the heart (should be more downside), the brain (should be more head-side (?)), liver?

That's actually something I didn't think of. The mass didn't protrude out of it, it was inside the larva's body, and it looked like something inside the mass was pulsating. I'm no expert on the internal anatomy of newts, but I don't think that it was supposed to be the heart.

Edit: Thanks for the response Daniel, I will see if I can make a drawing.

Here is a drawing- please excuse my drawing skills, I am not the best at computer generated art work. I hope it shows up...

Nathan, I'm so sorry they didn't make it

Could this thing have been something the larva swallowed right before it died? I can sometimes see food moving inside my lighter-colored larvae.