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E-Case #7
February 12-16, 2001
Heather Kelly-Hedrick, M.D.
HPI: 90 year old man presents for annual exam. No skin complaints.
Denies previous skin problems. No smoking history. No family history
of skin cancer. Does not report excessive sun exposure or history of
severe sunburns.
PMH: Severe hearing loss, h/o acoustic neuroma
O: Skin: Large number of pigmented, stuck-on appearing seborrheic keratoses
on face and trunk. A macular pigmented lesion on the right posterior
shoulder, some variation in color and an irregular border. It mearsures
2 cm in length by 1 cm in width. No lymphadenopathy.
Clinical Course: Referred to Dermatology. A 3.5 cm elliptical excision
done under local anesthetic. Entire lesion sent for histology. Surgical
pathology showed a highly atypical melanocytic proliferation consistent
with a melanoma arising within a dysplastic nevus. The deepest level
of dermal component measured 0.29 mm. No further surgery recommended
and close follow up in the dermatology clinic was arranged for ongoing
surveillance for signs of relapse or recurrence.
Discussion points:
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What features of the macule are consistent with
melanoma and more generally when should a pigmented lesion be considered
for biopsy?
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What are the risk factors for melanoma and non-melanoma
skin cancer, and what important primary prevention can be done?
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What is the best predictor of survival from melanoma
at the time of diagnosis?
Discussion for Ecase #7: Melanoma
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Asymmetry: Suggestive of melanoma
if the lesion is bisected and the halves are not identical.
Border irregularity: Suggestive of melanoma
if the border is uneven or ragged.
Color variation: Suggestive of melanoma
if there is more than one shade of pigment.
Diameter: Suggestive of melanoma if
the diameter is greater than 6 mm.
Other signs include irregularly pebbly surfaces, loss of normal skin
surface markings, satellite lesions, a rapid growth pattern (old lesions
that have changed or new lesions especially on palmar and plantar
surfaces), inflammation, crusting, or symptoms of bleeding, or sensory
change. In addition to looking, touching, stretching, pinching, rubbing,
moistening, and cross-illuminating can be helpful in assessing lesions.
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Risk factors for nonmelanoma skin cancer: Cumulative sun exposure
single greatest risk, increasing age, actinic keratoses precursors
of squamous cell CA, use of coal-tar products, tobacco and psoralens,
male sex, chronic skin ulcers, sinus tracts, burn scars, HPV, xeroderma
pigmentosum, previous history of skin cancer, white race, fair complexion,
red, blonde, or light brown hair, tendency to freckle and to burn
rather than tan.Risk factors for Melanoma: Intense, intermittent exposure
and blistering sunburns in childhood and adolescence, dysplastic nevi,
large number of benign pigmented nevi, early adulthood, age-related
incidence rises with increasing age, family history of melanoma in
a first (increases risk 8 fold) or second-degree relative, familial
atypical mole-melanoma syndrome, male sex, radiation exposure, immunosuppression,
other malignancies, previous skin cancer, xeroderma pigmentosum, giant
pigmented congenital nevi, whites, fair complexion, red, blonde, or
light brown hair, tendency to freckle and to burn rather that tan.
Primary Prevention: Limit exposure to strong sunlight, avoid midday
sun between 10 AM and 4 PM, avoid tanning booths, keep infants out
of sun completely, sunscreens regularly with at least SPF of 15, SPF
> 30 if outdoors for prolonged periods reapply sunscreens frequently
(every 2 hours) and liberally (reapply if sweating or swimming), wear
protective clothing (tightly woven fabrics, long sleeves), broad-brimmed
hat and sunglasses.
3. Tumor thickness is the single most important prognostic indicator
determining disease-free interval and ultimate survival of patients with
all subtypes of skin cancer.
References
Early detection and treatment of skin cancer. Am
Fam Physician. 62(2):357-68, 375-6, 381-2, 2000 Jul 15.
Overview of skin cancer detection and prevention for the primary care
physician. Mayo Clin Proc. 75(5):491-500,
2000 May.
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