It’s the 21st Century, Not the 19th
A little while ago, I was asked by one of my oncology colleagues to do a lymph node biopsy on one of his patients. The patient was a 67 year-old man with a cluster of enlarged lymph nodes in his right groin. His Primary Care doctor had rightly suspected lymphoma, a primary cancer of the lymph nodes, and referred him to oncology. The oncologist suspected lymphoma as well, and did CT scanning of the chest and abdomen that confirmed generalized enlargement of nodes in both places.
Lymphoma is a protean disease of the leukocytes or white blood cells. If the uncontrolled growth of leukocytes occurs mainly in the bone marrow, it manifests itself as leukemia. If the cancer occurs mainly in the lymph nodes, we call in lymphoma. It can arise from a number of different cell lines and the exact type of causative cell determines the specific diagnosis. It is important for the oncologist to know what type of lymphoma he is treating because that often determines what drugs are used.
Cell typing is done through a process called flow cytometry. I’m just a dumb surgeon and the biochemistry and immunology that go into this test are beyond my poor understanding. What I do know is that the pathologist needs a fairly large amount of tissue to do the test – about a cubic centimeter, say between the size of a grape and that of a peach pit.
I saw the man in my office and scheduled his biopsy or a few days later. At surgery, I took out a fairly large amount of tissue, partly to make sure the pathologist had enough, and partly to avoid cutting across a large node. That wasn’t because it would spread cancer but because nodes can bleed a lot and it’s better to take them whole if possible.
Cytometry requires fresh, unpreserved tissue. Nodes are sent fresh to the lab rather than dropping them in formalin in the OR. The more common reason we send tissue fresh is for a frozen section. That’s when the pathologist flash freezes the tissue with liquid nitrogen, cuts and mounts a slice, and looks at it immediately. We use this if we need a quick diagnosis. I hadn’t asked for a frozen section, but due to a mix up on the part of the cytologist or the OR nurse, one got ordered.
I was mildly surprised when the pathologist called into the room as I was completing the skin closure. I took the call because the room nurse said he was very insistent and sounded excited.
“What’s going on, Joe,” I asked as I came on the line.
“This node is full of caseating granulomas,” he said. “What’s this guy’s story?”
I was stunned. Caseating granulomas are the signature sign of tuberculosis. (Caseating means cheese-like and that’s what the inside of the nodes looks like – Brie cheese.)
This type of groin node used to be common a hundred and twenty years ago. Even a hundred years ago, it was a consideration when a patient presented with a groin mass. In 2014, TB is a Third World disease that is unfortunately making a comeback in this country. Even then, it’s more commonly seen in the lungs. Nodal involvement outside of the chest is rare.
This patient didn’t fit the profile of the usual TB patient. He wasn’t a recent immigrant, he wasn’t immunocompromised, he wasn’t an alcoholic or drug addict, and he wasn’t malnourished. He was a retired firefighter from Minnesota. So where had he gotten TB and why was it disseminated to his lymph nodes?
We still don’t have a good answer to that question. This was sort of a good news/ bad news scenario for him. On the one hand, he doesn’t have cancer. On the other hand, disseminated TB is a life threatening disease that takes a year or more to cure, if at all. TB has become resistant to some standard therapies and the drugs themselves have serious toxicities. He’ll need close monitoring and may need to be isolated for a while until we can be sire that he’s shedding the bacteria in his sputum and other secretions.
I’ve encountered this disease a few times in my career, but always in places like the Philippines or the outer South Pacific islands, places where TB is still endemic. I didn’t expect it here in my comfortable suburban practice. I’m glad the order got mixed up and the lymph node was examined immediately. At least now we have cultures and can check sensitivities to the standard drugs. Hopefully the man will do well.