NCCN Guidelines for Patients
Lung Cancer Screening, Version 1.2017
What happens after the first test? Types of lung nodules
Types of lung nodules
Screening with LDCT is used to find nodules in the
lungs. Nodules are small, round areas of abnormal
tissue. Nodules can be caused by cancer, infection,
scar tissue, or other conditions. Most nodules found
on LDCT are not cancer (benign). People can have
one lung nodule or more than one nodule found
Have features that can be used to tell if it is
cancer or not.
That are completely calcified (lots of calcium)
and that contain fat are not cancer.
That are cancer often have rough edges (called
That are cancer often grow faster and are larger
in size than nodules that are not cancer.
Many of the nodules found on screening are small,
about the size of a pea, and most of those nodules
are not cancer. Nodules are measured in mm
(millimeters). This letter “
” is about 1 mm long.
Doctors assess the density of a nodule. The density
of a nodule is a clue to whether the nodule is cancer
or not. Density is how solid versus hazy a nodule
looks on the LDCT pictures. Nodules are divided into
three groups based on density:
Solid nodules look about as solid as your
muscle does on an LDCT picture.
Non-solid nodules look like a fuzzy or hazy
cloud on an LDCT picture. These nodules
are also called a “ground-glass opacity” or a
Part-solid nodules have both solid and non-
solid areas in them. These nodules are also
called “semi-solid nodules” or “subsolid
Solid nodules are the most common kind of nodules.
Non-solid nodules are usually followed by more
LDCT tests. Even if the non-solid nodules are cancer,
these are considered the kind of cancer that will not
grow and spread. The part-solid nodules have the
greatest chance of being lung cancer.