Swelling hints at deeper malaise
When 40-year-old John Tang (an assumed name, for reasons of patient confidentiality) first came down with a fever, sore throat and enlarged lymph nodes on both sides of his neck - classic symptoms of an upper respiratory tract infection - his doctor prescribed antibiotics and sent Tang home to rest.
But Tang's fever persisted even after he popped the last pill. The swelling in his lymph nodes, which are bean-shaped collections of infection-fighting cells found throughout the body, didn't subside.
Tang's doctor then performed a standard investigative procedure for enlarged lymph nodes called fine needle aspiration. A slender needle was inserted into the enlarged lymph node to extract cellular material. This was used to determine whether a more insidious cause, such as tuberculosis or cancer, lay beneath. But Tang's test drew a blank.
For three weeks, his lymph nodes continued to enlarge while he faded in and out of fevers. Finally, doctors removed one of the lymph nodes for further tissue tests - known as a biopsy - and found lymphoma. This is a cancer of the lymphatic cells of the immune system.
In lymphoma, the lymphocytes - the white blood cells - become abnormal (cancerous). Instead of protecting him, part of Tang's immune system was now threatening to kill him. He was referred to Dr Raymond Liang, director of the Comprehensive Oncology Centre at the Hong Kong Sanatorium and Hospital.
The next challenge was to narrow down the type and extent of Tang's lymphoma to ensure an accurate prognosis and treatment plan. This was done through special tests, such as the monoclonal antibody test, which detects specific antigens (substances which trigger the production of antibodies).
PET - or positron emission tomography - scans were used to determine the affected lymph nodes more clearly, and a bone marrow biopsy was carried out to determine whether the cancer had affected Tang's bone marrow.
Liang found that Tang had diffused large B-cell lymphoma, a common type of lymphoma that accounts for about two in five of all cases. With the lymph nodes in his neck, armpits and abdomen all affected, he was classified as having stage-three lymphoma, in which the cancer had spread to both sides of his diaphragm.
The causes of lymphoma are unknown in more than 90 per cent of cases. The survival rate for this type of cancer is fairly good for sufferers under age 60 if they get the right treatment, Liang says.
In stage one, where the cancer is found in only one region, there's an 80 per cent chance of survival. In stage two, where two regions or more on the same side of the diaphragm are affected, it drops to 60 to 70 per cent. When the cancer has penetrated the bone marrow and spread outside of the lymphatic system, the patient is in the fourth and final stage. Even so, the rate of survival is as high as 40 per cent.
Tang, at stage three, had a 50 per cent chance of beating the cancer. The caveat: he had to be able to withstand the aggressive treatment, which involved chemotherapy and complementary radiotherapy.
Surgery is not a good treatment option, Liang says, because lymphoma tends to be widespread. A bone marrow transplant is usually the last resort for patients who have relapsed or are at high risk of doing so. Fortunately, Tang had age and a relatively early detection on his side. After six months of treatment, he is now in remission.
Liang notes that Tang's case highlights the importance of doing a biopsy early if lymphoma is suspected. This is because the small sample size obtained through fine needle aspiration cannot accurately reveal lymphoma.
Often, the giveaway for lymphoma is the persistent presence of enlarged and painless lymph nodes. If it is just a regular infection, the lymph nodes typically enlarge with white blood cells, but they usually feel tender and the swelling subsides when the infection is cured. Another telltale sign is enlarged nodes - commonly found in the neck, armpits, abdomen and groin - in more than one region.
Two underlying conditions may be complicated by chemotherapy, Liang says, as the treatment suppresses the immune system. Hepatitis B-positive patients run the risk of activating the dormant infection, which can result in fatal liver failure. HIV-positive patients, who are more likely to develop lymphoma in the first place, may be more prone to infections after chemotherapy treatment.
But overall, given the right treatment, lymphoma is a curable disease, Liang says.