General Information
Dermatopathology is the pathology subspecialty concerned with the
diagnosis of skin disease. Board-certified dermatopathologists complete
primary training in dermatology, pathology, or both, and then an additional
one to two years of specialty training in dermatopathology. The Yale
Dermatopathology Service has four full-time dermatopathologists who
hold joint appointments in the Department
of Dermatology and the Department of Pathology.
Dermatopathology services at Yale include the routine processing
of formalin-fixed specimens (wet tissues) and a range of special histochemical
and immunohistochemical staining services. In addition, specialized
services such as direct and indirect immunofluorescence studies,
electron
microscopy, tissue culture, and frozen immunohistochemistry can be
performed with properly submitted tissue specimens. Sensitive molecular
tests such as DNA in situ hybridization and the polymerase chain
reaction (PCR) can also be applied in cases where standard techniques
fail to
provide an answer. Consultative (second opinion) cases are also routinely
received from physicians outside the Yale system.
About Malignant Melanoma
Malignant melanoma is a potentially lethal melanocytic neoplasm with
a propensity for distant metastases. It may arise de novo, or in association
with a pre-existing nevus.
Malignant melanoma continues to present a significant public health
problem. Melanoma is one of the few remaining cancers with an increasing
incidence rate, and its incidence is rising faster than that of any
other cancer in the U.S. At current rates, 1 in 74 Americans will
develop melanoma during his or her lifetime.
This year, it is estimated
that
47,700 cases of invasive malignant melanoma and 20,000 to 40,000
cases of melanoma in situ will be newly diagnosed in the U.S. Deaths
from
malignant melanoma are also increasing: the mortality rate from
malignant melanoma has risen about 2% annually since 1960.
This year,
it is
estimated that 7,700 people will die from malignant melanoma in
the U.S. Survival
of patients with malignant melanoma is directly related to early
detection. Although multiple factors influence survival, thickness
of the tumor
has been shown to be the most important factor across multiple
studies.
Diagnosis of Melanoma
Diagnosis of melanoma depends on clinical identification with histopathologic
confirmation. To rule out melanoma in a clinically suspicious
lesion, an adequate biopsy must be performed and the specimen should
be
evaluated by a dermatopathologist or a pathologist experienced
in the evaluation
of pigmented lesions.
Malignant melanomas can be recognized using the following ABCD criteria:
Asymmetry. Melanomas grow
at an uneven rate resulting in an asymmetric pattern.
Border (irregularity). Melanomas
usually have an irregular border.
Color (variegation). Lesions
of melanoma show different colors: shades of black, light and dark
brown, as well as blue and white.
Diameter. Melanocytic lesions
with ABC features and diameters of greater than 6mm should be considered
suspicious for melanoma.
Prevention of Melanoma
Melanoma may be virtually preventable with simple behavioral
changes, such as avoidance of acute sun exposure resulting
in sunburn, which
remains a significant risk factor for the development of melanoma.
There are numerous other potential risk factors, including
blue/green eyes, blonde or red hair, light complexion, freckles, sun
sensitivity
and an inability to tan, immunosuppression, and history of
melanoma in a first-degree relative.
Environmental factors that increase the risk for malignant
melanoma include living near the equator, working outdoors,
and having
primarily outdoor recreational habits. Furthermore, people
who have had one
malignant melanoma are at an increased risk of developing
another.
By routine self-examination of the skin, the patient can
notice unusual moles which may represent early malignant
melanoma,
at a time when
such lesions are thin and curable.
Since 1985, the American Academy of Dermatology has sponsored
free annual National Melanoma/Skin Cancer Prevention
Campaigns. As of
the year 2000, over one million people have been screened
and thousands of melanomas have been detected, most in
their earliest
and curable
stages.
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Frequently Asked Questions
How do I biopsy a pigmented skin lesion?
Prior to biopsy, measure the lesion and submit the clinical dimensions
along with the requisition. Photographs, if available, are a wonderful
way to provide clinical documentation for the pathologist. Please
let the lab know if images need to be returned.
In almost all cases, especially for atypical moles, an excisional
biopsy is recommended. In general, the excision should extend
into the subcutaneous
fat and should clear the clinically-evident margins by 1-2 millimeters.
If a complete excision is not feasible, a broad shave biopsy or
saucerization that begins and ends several millimeters beyond
the clinically-evident
borders is appropriate. Ideally, the specimen should be submitted
on a small piece of paper or cardboard prior to immersion in
formalin (a portion of the wrapper used for surgical gauze is often
handy).
This prevents rolling of the specimen.
Punches can be used for punch-excisions only if they are a millimeter
or more larger than the clinically-evident lesion. Partial
biopsy of large melanocytic lesions by any method should be avoided,
and may
lead to serious diagnostic pitfalls.
If an excisional sample is not tenable, an incisional biopsy
is permissible, but in that case, it is mandatory that the
pathologist be provided
information about circumscription, symmetry, and duration.
The fixative of choice is 10% buffered formalin. Other fixatives
(especially those containing alcohol) alter the cytologic
characteristics of the
cells, unnecessarily complicating histopathologic evaluation.
If there are questions about these techniques, please contact
our
laboratory at (203) 785-4094.
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People
Jennifer
McNiff, M.D., Director, is Associate Professor of Dermatology and Pathology and Attending Dermatopathologist, YNHH. Her clinical
interests
include cutaneous lymphomas and clinicopathologic correlations.
Shawn E. Cowper, M.D., is Assistant Professor of Dermatology and Pathology
and Attending Dermatopathologist, YNHH. His clinical interests include
nephrogenic fibrosing dermopathy, alopecias, and informatics.
Earl J.
Glusac, M.D., is Associate Professor of Dermatology and Pathology
and Attending Pathologist, YNHH. His clinical interests include cutaneous
lymphoproliferative and melamocytic lesions.
Rossitza
Z. Lazova, M.D., is Assistant Professor of Dermatology and
Pathology and Attending Dermatopathologist, YNHH. Her clinical interests
include melanocytic neoplasms and soft tissue tumors.
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