Diagnosis Requires Biopsy
There seems to be some confusion about how dermatologists can
diagnose melanoma, the most serious form of skin cancer. To set the
record straight, studies are looking at how to diagnose melanoma
without a biopsy and researchers are making progress. It is,
however, not yet possible to tell if a patient has melanoma or any
type of skin cancer without a biopsy.
What New Tools Can Do
Part of this confusion may come from the technological advances that
have given dermatologists new tools and methods for examining the
skin. Designed to give dermatologists a better view, these tools can
help dermatologists decide whether a lesion should be biopsied. None
of these tools can tell the dermatologist if a suspicious lesion is
skin cancer. At least, not yet.
The dermatoscope is the most widely used of these devices.
Dermatologists use this handheld device to magnify and illuminate
lesions that could be melanoma. A magnified view helps
dermatologists determine if a lesion suspected of being a melanoma
should be biopsied. This, in turn, improves detection of melanoma
and reduces the need for unnecessary biopsies. It does not eliminate
the need for a biopsy
One device that has been making headlines is called the confocal
scanning laser microscope. It may be referred to as CSLM (and
sometimes CLSM or LSCM). This device directs a low-power laser beam
onto the skin. As the beam hits the skin, a series of views are
collected, assembled, and evaluated using specialized software. The
resulting information gives the dermatologist a better view of what
Collecting this information can help dermatologists detect lesions
that could be skin cancer. This tool cannot tell if a suspicious
lesion is skin cancer. Only a biopsy can do that, but the tool can
help the dermatologist evaluate suspicious lesions and decide if the
lesion should be biopsied. This device is not yet widely available.
One type of confocal microscopy that you may have heard about is
reflectance confocal microscopy (RCM). This novel imaging
technique uses a low-power laser beam to scan the skin and produce a
highly detailed image of a suspicious lesion, giving the
dermatologists an almost cellular view. In studies, dermatologists
have been able to find actinic keratoses (AKs), basal cell
carcinomas, and melanomas before the biopsy confirmed the finding.
RCM holds much promise as a non-invasive technique, but more
research is needed.
Two other imaging techniques that are being investigated are
optical coherence tomography (OCT) and reflex transmission
imaging (RTI). OCT is routinely used to examine lesions on the
eye. Its helpfulness in looking at lesions on the skin has not been
fully studied. RTI is a type of ultrasound. Its future as a useful
tool for detecting melanoma is not clear. More studies are needed.
While these devices and techniques cannot diagnose skin cancer, they
give dermatologists a closer look at suspicious skin lesions. This,
in turn, can help dermatologists find suspicious lesions earlier
than before and better determine whether a biopsy is needed. None of
these devices can confirm that a suspicious lesion is skin cancer.
Only a biopsy can tell us for sure. At least for now.
Casagrande Tavoloni Braga J, Scope A, Klaz I et al. “The
significance of reflectance confocal microscopy in the assessment of
solitary pink skin lesions.” Journal of the American Academy of
Dermatology 2009. [article in press]
Goodson AG, Grossman D. “Strategies for early melanoma detection:
Approaches to the patient with nevi.” Journal of the American
Academy of Dermatology 2009; 60: 719-35; quiz 36-8.
Segura S, Puig S, Carrera C et al. “Development of a two-step
method for the diagnosis of melanoma by reflectance confocal
microscopy.” Journal of the American Academy of Dermatology
2009. [article in press]
content solely developed by the American Academy of Dermatology
cancer biopsy (removing the suspicious lesion or part of
it) can be performed in a dermatologist’s office in
about 5 minutes with minimal discomfort.