Hemograms consist of both quantitative data (total cell counts, differential cell counts, red cell indices, etc.) and qualitative data (blood film morphology). Proper interpretation depends on the integration of both.
Accumulations of excessive fluid in the pleural, peritoneal, or pericardial space represent edema of these body cavities. As such, the dynamics of fluid accumulation are governed by Starling's law. In general, pleural, peritoneal, and pericardial effusions can result from either inflammatory or non-inflammatory causes.
Before considering pathologic cytology of lymph nodes, it is necessary to define normal lymph node cytology. Aspirates from normal lymph nodes contain mixed cell populations in which small lymphocytes are the predominant cell (>80 percent of all cells).
Of all the diagnostic tests available, blood evaluation is one of the single most valuable tools in assessing the general health of the body. Blood, and the nutrients it carries, circulates through every living cell in the body.
In cytology, cells that are properly smeared and stained can be described as "fried eggs" because of the similarity in the appearance of the nucleus and cytoplasm to the egg yolk and white. If the preparation is too thick, or is improperly stained, the cell outline may be seen, but intracellular detail will not be visible.
Lymph node sampling and cytology is quick, easy, and usually rewarding. Cytologic samples of peripheral and/or internal lymph nodes may be collected by fine-needle aspiration biopsy or nonaspiration fine-needle biopsy techniques.
Cytologically, neoplasia is characterized by the presence of a homogeneous population of cells that have come from the same tissue of origin. This is best appreciated by the presence of cells with the same cytoplasmic characteristics.