Blood Cancer Under the Microscope

One of the older methods of medical imaging is still in use today – light microscopy. When it comes to diagnosing the exact kind of cancer, or monitoring for relapse, scientists have fortunately developed a number of additional tools since the time the light microscope was invented, including body scans in medical imaging and testing for biologic markers in the blood.

Still, microscopic appearance of the malignant cells even today often plays an important role in diagnosis and classification of leukemia and lymphoma and may be a factor in determining the grade or aggressiveness of a given malignancy. Although today’s doctors often evaluate cancers on the level of their individual genes and mutations, sometimes a picture is still worth a thousand words. Here are a few images showing microscopic views of a kind of leukemia, a kind of lymphoma and a killer T cell being used to attack a cancer cell.

1
Hodgkin Lymphoma

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Light microscopy. Hodgkin lymphoma with Reed-Sternberg cells.

This slide shows a case of Hodgkin lymphoma, sometimes called Hodgkin’s disease. Hodgkin's disease can occur in both children and adults, however, peak ages are in the 20s and 70s/80s. In this case, it’s not the patient’s blood that has been viewed under the microscope; rather, it’s a section or slice through a lymph node affected by Hodgkin disease—a cancer of white blood cells or lymphoma cells. The blue cells that have the appearance of owl's eyes are called Reed-Sternberg cells are the hallmark cells of Hodgkin lymphoma. They look like owls when stained so as to be visible, and here two lobes can be seen. The American Cancer Society estimates that about 9,190 new cases of Hodgkin lymphoma are diagnosed each year.

2
Chronic Myelogenous Leukemia

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Light microscopy. Chronic myelogenous leukemia.

On the associated image of a peripheral blood smear of a patient, the blue stained cells represent white blood cells that are increased in number, something that's consistent with chronic myelogenous leukemia (CML). A lot of other things could cause a high count, but CML was the cause in this case. CML can also be called chronic myeloid leukemia or chronic granulocytic leukemia. CML most commonly affects older adults and rarely occurs in children. People can have CML for a long time without knowing it. CML is associated with something called the Philadelphia chromosome, an extra-short chromosome named after the city where it was discovered. Some 90 percent of people with CML have blood cells with the Philadelphia chromosome. Only about 10 percent of leukemias are CML. The American Cancer Society estimates that about 5,980 new cases will be diagnosed each year.

3
Human Immune Cell Killing a Cancer Cell

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Artist's rendition of killer T versus cancer, as seen using scanning electron microscope.

Here we see a killer T cell (the smaller cell below the cancer cell in this image) interacting with a cancer cell. This is actually an artist’s rendition, but it’s based on reality. Scanning electron microscopes generate similar images. Killer T cells are immune cells that can kill certain other cells, including foreign cells, cancer cells and cells that have become infected by a virus. According to the National Cancer Institute, killer T cells can be grown in the laboratory, and then transferred into a patient to kill cancer cells. Killer T cells are white blood cells, and more specifically, they are a type of lymphocyte. Killer T cells may also be referred to as cytotoxic T cells and cytotoxic T lymphocytes.

Sources:

Barrett DM, Singh N, Porter DL, Grupp SA, June CH. Chimeric Antigen Receptor Therapy for Cancer. Annu Rev Med. 2014;65:333-347.

El-Galaly TC, Mylam KJ, Bogsted M, et al. Role of routine imaging in detecting recurrent lymphoma: A review of 258 patients with relapsed aggressive non-Hodgkin and Hodgkin lymphoma. Am J Hemat. 2014;89(6):575-580.

American Cancer Society. Chronic Myeloid Leukemia (CML).

American Cancer Society. What are the key statistics about Hodgkin disease?

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