1.General concept of leukemia and lymphoma A: First, let’s talk about the general concept. Leukemia: usually refers to a state in which malignant blood tumor cells appear in the bone marrow and peripheral blood. The usual standard is that if the malignant tumor cells in the bone marrow or peripheral blood exceed 20%, it is called leukemia. If the malignant blood tumor cells are lymphocytes, it is called lymphocytic leukemia; if they are granulocytes, it is granulocytic leukemia; if they are NK cells, it is NK cell leukemia. Depending on the course of the disease and the degree of differentiation, it can also be classified as acute or chronic. Lymphoma: It is a malignant tumor of lymphocytes, usually starting as a mass (lump, mass), and this form is customarily called lymphoma; but in fact, it can also start as leukemia, which is lymphocytic leukemia. Therefore, lymphoma broadly includes lymphocytic leukemia. 2. Judgment of lymphoma/leukemia: examples A: After my first answer, are you still a little confused? Here are a few examples to explain: (1) First, let’s take the most common lymphoma, diffuse large B-cell lymphoma, as an example. Diffuse large B-cell lymphoma usually starts as a mass. For example, a patient with a mass in the neck has a biopsy and is diagnosed with diffuse large B-cell lymphoma. If there are lymphoma cells in the bone marrow, but the percentage is not high enough, we usually call it “lymphoma bone marrow invasion”, and this patient is a stage IV patient. lymphoma leukemia”. There are also patients who did not have lymphoma at the beginning, but then had it in the bone marrow after the treatment was not effective, and the diagnostic criteria are the same. Note that this is just a different manifestation of the same tumor or different stages of development, not that lymphoma at the beginning and then leukemia are two types of tumors, but just different stages of one tumor. Of course, the invasion of bone marrow is more serious than the non-invasive bone marrow. (2) Lymphoma that often starts as leukemia. Lymphoblastic lymphoma/acute lymphoblastic leukemia: This is currently considered to be a disease that sometimes starts as a leukemia and sometimes as a lymphoma (a swelling or mass), usually more often in the form of a mediastinal swelling for those of T-cell origin and more often in the form of leukemia for those of B-cell origin. As an example, a patient had a hoarse voice at the onset of the disease, and a large mass in the mediastinum was found on CT. However, after more than a year, there was a sudden increase in leukocytes, and a bone aspiration revealed a large number of leukemia cells, which was diagnosed as acute lymphocytic leukemia. Chronic lymphocytic leukemia: Small B-cell lymphoma also often starts as leukemia, similar to the above example. However, unlike the above, this type of lymphoma is very inert, regardless of the form in which it starts. 3. Is it possible to have lymphoma and leukemia at the same time? After my answer above, is it easier to answer this question? It is possible. For example, if a patient with acute T-lymphocytic leukemia, which is already manifested as leukemia, is accompanied by enlarged lymph nodes, then if the pathological diagnosis is made by excision, it is T-lymphoblast lymphoma, so there is both leukemia and lymphoma. However, it should be noted that this is not a case of two diseases, but only one type of lymphoma, and the treatment is only for this one disease. It is important to note that in rare cases, for example, a patient who has chronic myeloid leukemia and later develops lymphoma, this is different. This is not the same for this patient. 4. Do these patients have to undergo hematopoietic stem cell transplantation? Patients with bone marrow invasion are usually more severe (stage IV lymphoma with bone marrow invasion), but the need for HSCT does not depend entirely on this. For example, follicular lymphoma or small cell lymphoma, even if they have bone marrow invasion, usually do not require a HSCT because of their slow growth. Therefore the decision to transplant does not depend entirely on the presence or absence of bone marrow invasion.