Page 252 - Clinical Hematology Atlas

236 SECTION FIVE MISCELLANEOUS

TABLE 24-1 Characteristics of Benign and Malignant Cells

Benign Malignant

Occasional large cells Many cells may be very large
Light to dark staining May be very basophilic
Rare mitotic figures May have several mitotic figures
Round to oval nucleus; nuclei are uniform size May have irregular or bizarre nuclear shape
with varying amounts of cytoplasm
Smooth nuclear edge Edges of nucleus may be indistinct and irregular
Nucleus intact Nucleus may be disintegrated at edges
Nucleoli are small, if present Nucleoli may be large and prominent
In multinuclear cells (mesothelial), all nuclei Multinuclear cells have varying sizes and shapes of
have similar appearance (size and shape) nuclei
Moderate to small N:C ratio May have high N:C ratio
Clumps of cells have similar appearance Clumps of cells contain cells of varying sizes and
among cells, are on the same plane of focus, shapes, are “three-dimensional” (have to focus up
and may have “windows” between cells and down to see all cells), and have dark staining
borders; no “windows” between cells
From Rodak BF, Fritsma GA, Keohane EM: Hematology: clinical principles and applications, ed 4, St. Louis, 2012, Saunders.
N:C, Nuclear:cytoplasmic.

It is not always possible to distinguish malignant cells from mesothelial cells with the sole
use of the light microscope. The following criteria for malignant cells may aid in this
distinction.

NUCLEUS: High N:C ratio, membrane irregular
Nucleoli: Multiple, large with irregular staining
Chromatin: Hyperchromatic with uneven distribution
CYTOPLASM: Irregular membrane

NOTE: Smears with cells displaying one or more of the above characteristics should be referred
to a qualified cytopathologist for confirmation. See Table 24-1 for a comparison of benign and
malignant features. Malignant cells tend to form clumps with cytoplasmic molding. The
boundaries between cells may be indistinguishable.