In this unit we are going to look at several aspects of lymph node pathology, both benign and malignant. Remember that the lymph nodes are potentially catching a lot of "floating" and foreign material, so they frequently become secondarily involved in many conditions. Because of this property we are going to look at them in situations you might not at first suspect. Furthermore, we are going to look at situations in which proliferative conditions of the lymphatic system involve organs as an "innocent bystander." There are a number of organs that may not leap to mind as harboring a great deal of lymphatic tissue, but there are. Consider for example the bowel. The most common primary malignant tumor of the small bowel happens to be a malignant lymphoma. Not surprising once one considers the large amount of lymphatic tissue in the lamina propria throughout the small bowel. But before going to the slides and descriptions, here are a couple of suggestions and "helpful rules" for interpreting microscopic sections of lymph nodes.

By now, it should be ingrained in your thinking to look at a slide on a white background before putting it on the stage of the microscope. It's doubly important in the case of lymph nodes. This visual assessment will often provide much information about the extent of replacement or involvement of the node with whatever process afflicts it. Also, when assessing a lymph node, keep in mind the node should have a characteristic microscopic architecture. That is, a capsule, subcapsular sinuses, cortical tissue and cortical sinuses, and so forth. We always look at all aspects of the lymph node, and assess the degree of effacement of the nodal architecture. That is to say the degree of replacement of the expected nodal architecture with whatever disease process is going on. The description and understanding of what is meant by "the either complete or partial effacement of a lymph node" is not only crucial to recognizing the underlying disease process, it is crucial to your grade. Questions about this term will come up on the test, and you can bet when you are asked to diagnose a slide with a malignant lymphoma, I'm going to looking for the appropriate terminology in your write-ups.  Although there are a number of slides in this unit, I'd recommend taking a little extra time, and possibly going over your observations with a friend. Good luck.

Slide 30, soft tissue plasmacytoma of spleen.	Slide 57, spleen with Hodgkin's disease.	Slide 57, Hodgkin's disease in spleen.	Slide 60, lymph node with malignant lymphoma.	Slide 62, Hodgkin's disease in a lymph node.	Slide 62, Hodgkin's disease in a lymph node.
Slide 67, spleen with sickle cell crisis.	Slide 69, liver with chronic lymphocytic leukemia.	Slide 69, spleen with chronic lymphocytic leukemia	Slide 77, lymphatic tuberculosis.	Slide 84, lymph node with reactive hyperplasia.	Slide 102, pituitary with histiocytosis.
Slide 102, pituitary with histiocytosis, a higher power view.	Slide 111, lymph node with metastatic breast cancer.	Slide 111, lymph node with metastatic breast cancer	Slide 114, splenic infarct.	Slide 118, lymph node with metastatic malignant melanoma.	Slide 123, another splenic infarction.
Slide 124, spleen with amyloidosis.	Slide 130, spleen with chronic splenitis.	Slide 142, malignant lymphoma of small bowel.	Slide 146, malignant lymphoma of testis.	Slide 160, malignant lymphoma of salivary gland.	Slide 160, malignant lymphoma of salivary gland
Slide 167, another example of intestinal lymphoma.	Slide 176, Lymph node, metastatic seminoma	Slide 191, Lymph node, Hodgkin's disease	Slide 197, follicular lymphoma	Slide 206, follicular lymphoma	Normal lymph node
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Normal spleen

Mark Braun, MD braunm@indiana.edu
Copyright 1998, the Trustees of Indiana University