Lymphoma is a cancer (actually, a set of cancers) which attack cells in the body's immune system, or lymphatic system. The care team for a person diagnosed with lymphoma will typically involve at least three types of doctors. First, a general practitioner or family doctor provides primary care, and is usually the first point of contact when a person with suspicious symptoms searches for medical help. Second, oncologists are doctors who specialize in the treatment of cancer, including lymphoma. Finally, hematologists are doctors who specialize in treating blood disorders, including problems in the immune system such as lymphoma.
Lymphoma is more a category of cancers than a specific type of cancer. Traditionally it is divided into Hodgkin's disease (about 25% of new cancers) and non-Hodgkin's lymphoma (all of the rest), even though there are over a dozen different types of non-Hodgkin's lymphomas. In addition, some types of non-Hodgkin's lymphoma, like diffuse large B-cell lymphoma, are very aggressive and immediately dangerous, whereas others, like follicular lymphoma, are very slow-growing (known as indolent) and may take years before they have become genuinely threatening. There are often few symptoms of even advanced lymphomas, other than one or more painless, growing lymph nodes, so many people do not even realize they are sick until the disease is relatively far along.
The first point of contact, and member of a care team, will be a person's primary care physician, typically their family doctor (aka general practitioner, or GP). Family doctors are generalists rather than specialists, trained to identify suspicious cases, order and interpret tests where necessary, but then refer cases of advanced diseases to specialists for treatment. People who have family doctors will typically have much longer and better relationships with them than with other doctors, and are already accustomed to having most of their medical needs dealt with by him or her.
Next, all cases of cancer ultimately end up being passed to an oncologist. Oncologists are doctors who specialize in the diagnosis and treatment of all forms of cancer. An oncologist will be most familiar with current practices in terms of cancer treatment, and best able to discuss a given person's options going forward. Oncologists, particularly those involved in medical research, may specialize in a given type of cancer, and depending on your location and your means, it may be possible to bring your case to an oncologist who specializes in lymphoma.
Third, lymphomas are often also referred to hematologists, specialists who deal with blood disorders. Although hematologists technically study blood disorders, they are usually also well-versed in disorders affecting the related lymphatic system, and - because there are certain forms of cancer which are serious diseases of the blood - have often also studied oncology. Hematologists, along with oncologists, may be able to provide recommendations and make informed judgements about aspects of treatment, including chemotherapy and, where it is an option for particularly advanced lymphoma, stem cell and bone marrow transplants.
Depending on the type of care required, a number of other medical specialists may be brought in to consult on particular aspects of a case. For instance, there are pain and palliative care specialists who focus on reducing discomfort and improving quality of life, particularly in late-stage disease. If the disease is caught early and is a candidate for radiation treatment, a radiation oncologist may oversee that procedure; if a biopsy is performed, a surgeon may be necessary for that procedure. Certain X-rays and other internal scans must be interpreted by a qualified specialist, known as a radiologist.
Today, managing cancer involves assembling a care team of specialists from a diverse range of professions. Some - nurses, social workers, nutritionists, pharmacists, psychologists, and so on - will not even be doctors. However, in the case of lymphoma, specialists from several different fields may play a close role in treatment, particularly including oncologists and hematologists.