PLEASE HELP: Lump in hen's neck, getting worse. See photo

Well, since you "snipped into it" - I'm assuming you found no pus or oozy stuff?  How deep did you go? What DID it look like?  Tissue? Fat?  what does it feel like?  Hard? Squishy? Will it move easily around or is it fairly stationary when you try to move it? My first thought was a round of stiff antibiotics - like penicillin.  But if it wasn't a pus pocket - I'm kind of at a loss.

What was inside the lump?  We need to know in order to help you.

Did the blood come from the skin being cut or did you actually cut into the lump?  If the lump is vascular then it sounds like it may be a tumor.  It is not out of the realm of possibility that she has a tumor, but an abscessed infection is much more common in birds.

When you cut into the lump - you say there was blood in it... were you able to "deflate" the lump by emptying out the blood?  Or was it just bloody from being cut open...  If it's an abcess, you should be able to at least partially deflate it by squeezing out the pus (which may even look bloody if mixed with enough blood), but if it is solid, then it's probably a tumor. 

There was nothing other than blood in it?  No white, cottage cheese-like stuff inside?  I am still thinking infection is more likely than tumor, but if there was no evidence of infection then it must be a tumor.  Not much can be done about that other than euthanizing her when she gets too ill.

Does not matter now...      but, you should always do the home Q-tip test to test for gapeworms before treating for it.  It's pretty rare.  Also, I don't think Safeguard will treat it anyway...    so, if she did have it, which is doubtful, the safeguard would not have taken care of it.

Listen to CMV, good advice there, always.

Best of luck...   If you can find one, have one nearby, can take her to a poultry certified veterinarian, and if you can afford it, that might be the only thing you can do to possibly keep her alive.

Take care...