Selection of Site for Biopsy
For diffuse process, this is not crucial. For localized lesions, we
certainly have to select the site for biopsy. For the exact
selection of site, you require additional assistance. We have the
following options:
- Physical Exam
History and physical exam can help
select the site for biopsy. If there is persistent chest wall pain
and/or swelling on exam, then it is an ideal site for biopsy.
If the chest x-ray confirms the presence of a mass lesion
corresponding to the chest wall abnormality, one can proceed with
a biopsy without any other additional localizing procedures.
If the mass is large and close to the chest wall, certainly
dullness and other physical findings can help with selection of
site. However, if the mass lesion is surrounded by lung tissue,
physical exam will not be of help to select the site for biopsy.
- Fluoroscopy
Biplane fluoroscopy is ideal for most cases.
I use a C-arm fluoro unit. It is helpful for localization,
selection of site for port of entry and direction and placement
of the needle in the lesion. Following the procedure, you can also
evaluate the patient for pneumothorax.
- Ultrasound
Ultrasound can help select the site for
localization. The point of contact of the mass to the chest wall
is ensured if the ultrasound localizes the lesion; thus,
minimizing the risk of a pneumothorax. One can even precisely
place the needle into the lesion through the hole in the probe.
I found ultrasound ideal for pancoast lesions where fluoroscopic
localization is difficult. However, ultrasound is unable to detect
lesions surrounded by lung tissue unless the lesion is
deep in the chest.
- Computerized Tomogram
Computerized tomogram is ideal for
lesions that are small or deep in the chest and for mediastinal
masses. The needle can be placed in the lesion and confirmed in
the same sitting. It is certainly the best way to approach lesions
in the mediastinum where other modalities are not suited in
distinguishing the mass from other organs. Small lung lesions can
be biopsied with assurance of placement of the needle in the lesion
only with the guidance of computerized tomograms.
The disadvantage is the length of time the needle must remain in
the chest. It is cumbersome. Both the patient and physician do not
find it comfortable.