Dr. Kenneth F. More, M.D.

If you have persistently enlarged lymph nodes, you should see a hematologist or oncologist and consider an excisional lymph node biopsy. A simple fine needle aspiration is frequently insufficient and removing the entire lymph node for study is necessary. The doctors that remove lymph nodes are ENT surgeons or General surgeons, depending on the location of the enlarging, most suspicious lymph node.

The key is to now which cell line is low (white cells, red cells, platelets) and figure out why. It can be as simple as a nutrient deficiency, a benign inheritable cause, or as complex as a cancer that invades the bone marrow space.
If this count is stable, it may sometimes be watched over longer periods of time. If the blood count falls quickly, you may need an urgent work-up in order to not miss a dangerous condition.

This is an important question to answer in discussion with your surgeon and your oncologist, who frequently meet (together with pathologists, radiologists, radiation oncologists) in "tumor boards" to discuss cases and treatment options. The decision to operate depends on the health of the patient and the benefit of the surgery which arises from the STAGE of the colon cancer presentation. The stage describes how far the cancer has spread, along clinically demonstrated important criteria. The stages are described differently for every cancer.
Classic colon adenocarcinoma can be potentially cured by surgery for stages 0-3, but not typically in stage 4. In short, the details of the case matter very much.

Yes. There are several variations in sickle cell disease, and they are all the result of a mutation in one of the 2 protein chains that make up the hemoglobin molecule. Under stress and/or conditions of low oxygen tension, the mutated hgb molecule changes shape and polymerizes into a long stack of molecules (like a stack of legos) which deforms the round cell into a crescent or "sickle" shaped cell. These cells eventually break and cause anemia (or low red cells).

O neg is the classic universal donor.

A Patient with vague symptoms often requires long follow up with repeat testing and comparison imaging. The list of conditions which may cause your stated symptoms is long and range from chronic infection, to inflammatory states, to various hematologic cancers. In the US, Oncologists and Hematologists are frequently interchangeable and many are board certified in both specialities because of the overlap in topics.
Ultimately, a diagnosis of lymphoma or leukemia requires a biopsy for confirmation. Either a lymph node biopsy or a bone marrow biospsy. Sometimes peripheral blood testing (Flow cytometry, peripheral blood cytogenetics and FISH studies) can provide critical clues. You should definitely find a good Hematologist Oncologist to follow you for changes that might prompt a more rapid evaluation.

It very much depends on which blood disorder. Some are inheritable, some acquired. A list of blood disorders is dauntingly long, some benign and some very dangerous.

The RBC number is a calculated number and generally unhelpful. It sounds like you have already seen a hematologist, since they are commonly the ones who order flow cytometry tests and recommend bone marrow biopsies. An elevated population of NK cells can be reactive (a response to infection or inflammation) or may be a feature of LGL leukemia. If your counts continue to fall to less than "borderline levels," you should consider a formal Hematology/Oncology evaluation.

It depends on the blood disorder. Some blood cancers can be treated and even cured with cheomotherapy.