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U N I T 1 3
Integumentary Function
There are two types of basal cell carcinoma, deter-
mined by their pattern of growth: superficial basal
cell carcinomas originating from the epidermis and
extending upward, and nodular basal cell carcinomas
in which the tumor grows downward into the dermis.
Nodular basal cell carcinoma,
the classic type, pres-
ents as a small, flesh-colored or pink, smooth, trans-
lucent nodule that enlarges over time (Fig. 46-23).
Telangiectatic vessels frequently are seen beneath the
surface. Over the years, there is a central depression
that forms and develops into an ulcer surrounded by
the original shiny, waxy border.
Superficial basal cell
carcinoma
presents as a scaly erythematous patch or
plaque. Both nodular and superficial forms may con-
tain melanin, imparting a brown, blue, or black color
to the lesions.
Since basal cell carcinoma is highly curable if
detected and treated early, all suspected lesions should
undergo biopsy for diagnosis. The treatment depends
on the site and extent of the lesion. The most impor-
tant treatment goal is complete elimination of the
lesion. Also important is the maintenance of function
and optimal cosmetic effect. Curettage with electro-
desiccation, surgical excision, irradiation, laser, cryo-
surgery, and chemosurgery are effective in removing
all cancerous cells. Immune therapy, gene therapy,
and photodynamic therapy are emerging treatments.
Persons should be checked at regular intervals for
recurrences.
Squamous Cell Carcinoma
Squamous cell carcinomas are the second most common
malignant tumors arising on sun-exposed sites in older
people, exceeded only by basal cell carcinoma. In addi-
tion to sun exposure, occupational exposure to arsenic
(i.e., Bowen disease), industrial tars, coal, and paraffin
increase the risk for squamous cell carcinoma. Men are
twice as likely as women to have squamous cell carci-
noma. Black persons are rarely affected.
Squamous cell cancers are composed of tumor cells
that resemble the epidermal cells of the stratum spino-
sum to varying degrees and extend into the adjacent
dermis.
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There are two types of squamous cell carci-
nomas: intraepidermal (termed in situ carcinoma) and
invasive carcinoma.
Intraepidermal squamous cell carci-
noma
remains confined to the epidermis for a long time.
However, at some unpredictable time, it penetrates the
basement membrane to the dermis and metastasizes to
the regional lymph nodes. It then converts to
invasive
squamous cell carcinoma
. The invasive type of squa-
mous cell carcinoma can develop from intraepidermal
carcinoma or from a premalignant lesion (e.g., actinic
keratoses). It may be slow growing or fast growing with
metastasis.
Squamous cell carcinoma is a red, scaling, keratotic,
slightly elevated lesion with an irregular border, usually
with a shallow chronic ulcer (Fig. 46-24). The lesions
usually lack the pearly rolled border and superficial
FIGURE 46-23.
Nodular basal cell carcinoma, which presents
as a reddish-brown papule, often with telangiectatic blood
vessels, and a central depression with rolled borders. (From
National Cancer Institute Visuals. No. AV-8500-3608.)
FIGURE 46-24.
Squamous cell carcinoma as manifested by
a raised lesion of the skin of the face. (From National Cancer
Institute Visuals. No. AV-CDR728323. Courtesy of Kelly Nelson,
photographer.)
