Hi. Unfortunately, it's not a simple matter. But statistically, an enlarged node is not usually due to cancer.
The epitrochlear nodes are ones where docs say that you have to be concerned over cancer more so than most other locations. But I'm not sure that thinking is current.
Knowing the size of the node, whether it is increasing, and your own age would be helpful.
The association with the spleen could be cancer, or could be infection, or could be some mystery immune condition. We see more than a few people come through here with unusual immune conditions, some never get diagnosed precisely because the immune system is so complex.
Diagnosing thyroid conditions is much easier and linear. Following Occham's Razor, we'd have to wonder if some underlying process involving inflammation (not necessarily Hashi's) is causing everything.
You can find medical web pages saying that pain after alcohol is a strong sign for Hodgkin's Lymphoma (also a reason I asked your age). But there are alcohol threads here which seem to point to non-lymphoma causes, so that can be reassuring also.
I'd say that no one even knows if it is a node for sure, without a scan. Lipoma, cyst, granuloma are some possibilities. I don't quite see why they didn't do a sono of the node instead of looking elsewhere - unless the breast lesion was found early and they are mainly thinking of metastases.
Is the node rock hard (calcium)? If not (you probably would have said so if it was), nodes can get scar tissue inside (why I'd mentioned cat scratch disease, e.g.) A primary lymphoma tumor (starting there) would be rare, but possible.
Not to alarm you, but with bone pain and high serum calcium you want to be aware of Multiple Myeloma. IIRC, an x-ray can see lytic lesions. Where was your CT done? Did it include the lower spine?
Blood work? Well, a CBC more so for leukemia than early lymphoma or CLL - unless one or more counts are really noteworthy. No easy bruising? (when a blood cancer gets into the marrow, normal production of blood cells gets crowded out)
An ER is not a good place for diagnosis of unusual conditions. Your docs seem to be doing watch and wait, which seems fair at this point though very stressful for you. A sono of the node might see signs (fatty hilum, normal architecture in general) than would be very reassuring.
Itching (histamine) could be cancer or immune reaction.
Some pages:
http://www.aafp.org/afp/1998/1015/p1313.html#afp19981015p1313-t4
(Table 3 lists infection as first)
http://www.aafp.org/afp/2002/1201/p2103.html
another from that good site for FPs doing diagnosis
http://www.medhelp.org/posts/Leukemia--Lymphoma-/Lump-on-neck-2012-follow-up-/show/1970906
note: is it a node or not, two opinions from two docs
http://www.medhelp.org/posts/Leukemia--Lymphoma-/Swollen-Lymph-Nodes-after-alcohol-consumption/show/385680
alcohol pain and not lymphoma, plus there are others here
Let's see, what else... any Hx or Fx of cancer, frequent infections, autoimmunity, severe mono or any unusual immune conditions?