Lecture Notes Dermatology - Graham-Brown, Robin, Burns, Tony

88 Benign and malignant skin tumours
Treatment
Excision, biopsy and radiotherapy or, for superficial
tumours, curettage, cryotherapy or photodynamic
therapy; careful assessment of morphoeic
tumours is needed — a technique known as ‘ microscopically
controlled surgery ’ (Mohs’ surgery)
may be helpful because it allows prospective
delineation of tumour extent. It is particularly
important to deal adequately with lesions around
the eyes, nose and ears. The use of topical therapies
for superficial types, notably imiquimod (a
promoter of interferon - α ), has been pioneered
more recently.
Actinic or s olar k eratoses
These are areas of dysplastic squamous epithelium
without invasion, but actinic keratoses do
have low - grade malignant potential and their
presence indicates unstable epithelium.
Clinical f eatures
Red and scaly patches (Figure 9.11 ) that characteristically
wax and wane with time; many hundreds
of lesions may occur in heavily sun - exposed
individuals.
Sites of p redilection
Light - exposed skin, especially the face, forearms,
dorsa of hands, lower legs and bald scalp.
Differential d iagnosis
Lesions of chronic discoid lupus erythematosus
can be difficult to distinguish, and some are pigmented,
leading to confusion with lentigo maligna
(see below).
Treatment
Cryotherapy is best for small numbers of lesions;
large areas on the face and scalp can be treated
with the topical agents diclofenac sodium,
5 - fluorouracil, imiquimod; in very elderly patients
it may be best to do nothing.
Squamous c ell c arcinoma in situ
(or Bowen ’ s d isease)
Bowen ’ s disease is an SCC confined to the epidermis,
and is common below the knees in
elderly women. Invasive change does occur but
is rare.
Figure 9.11 Multiple solar keratoses.
Clinical f eatures
Usually a solitary patch of red scaly skin, although
multiple areas may occur; Bowen ’ s disease is
asymptomatic.
Variant
Erythroplasia of Queyrat —non-invasive dysplastic
changes may also occur on the penis, where the
clinical appearance is of a velvety red plaque.
Although given a separate name, it is essentially
the same as Bowen ’ s disease elsewhere.
Sites of p redilection
Light - exposed skin; may occur on non - exposed
areas such as the trunk.
Differential d iagnosis
There is a superficial resemblance to psoriasis
(Figure 9.12 ), but the surface scale is adherent
rather than flaky and removal of scale leaves a
glistening red surface, not bleeding. Arsenic was