2. “Intraepidermal” means that the cancerous cells are located in the
epidermis from where they originally developed (in situ).
Squamous cell carcinoma in situ (SCCIS) is a vitiated, superficial
growth of cancerous cells on the skin’s outer layer.
It is not a severe condition but could develop into a full form of
invasive skin cancer if not detected early or well managed.
Flat cells, known as squamous cells, are located in the epidermis.
They are responsible for the production of the keratin protein and
affected by this condition
3. Intraepidermal or squamous cell carcinoma in situ was first attributed to
exposure of unprotected body parts to ionizing radiation in the year 1920.
However, population studies today show that the most common cause of
carcinoma is long-term exposure of the skin and dermal layers to sunlight.
Ultraviolet radiation damages the skin cell nucleic acids, leading to the
mutation and cloning of the p53 gene. The resulting exposure to ultraviolet
UV radiation leads to a geometric growth of skin cells.
Auto function cell repairs also are impeded by exposure to ultraviolet (UV)
from sunlight.
Diseases or drugs capable of suppressing immune responses to skin
damage also can trigger the mutation of squamous cells.
Other causatives attributed to intraepidermal squamous cell
carcinoma include arsenic ingestion and some viral infections
4. Usually, squamous cell carcinoma in situ (SCCIS) affects sun-
exposed areas on the skin of the head and neck.There are also cases
of it arising on the trunk.
In the early stages of Bowen disease, virus lesions appear on the
skin in the form of red, scaly patches, and as it progresses, it
develops into nodules or plagues which are prone to ulceration.
-Bowen disease-
6. Squamous cell carcinoma of the skin most often occurs on sun-exposed skin,
such as your scalp, the backs of your hands, your ears or your lips.
But it can occur anywhere on your body, including inside your mouth, the
bottoms of your feet and on your genitals.
Signs and symptoms of squamous cell carcinoma of the skin include:
1. A firm, red nodule
2. A flat sore with a scaly crust
3. A new sore or raised area on an old scar or ulcer
4. A rough, scaly patch on your lip that may evolve to an open sore
5. A red sore or rough patch inside your mouth
6. A red, raised patch or wartlike sore on or in the anus or on your genitals
7. Dermoscopy can be helpful for diagnosing pigmented intraepidermal
carcinoma (Bowen disease, squamous cell carcinoma in situ) which
presents as ,
1. an irregular skin-coloured, pink or brown scaly plaque.
2. Irregular clusters of so-called ‘glomerular vessels’ (coiled vessels) and/or
globular vessels (small red clods) are characteristic.
3. They may be associated with a scaly surface, small brown globules,
linear greyish dots and/or homogeneous pigmentation.
4. Pigmented structures may be seen arranged in lines.
5. White circles may be present, often in irregular clusters.
6. There may be superficial erosion and crusting.
8. Biopsy- The gold standard of diagnosis for carcinoma in situ is a
skin biopsy; a shave or punch biopsy can be used. Biopsy samples
should be taken from the suspected carcinoma in situ and its
surrounding tissues and then sent to a dermatopathologist for
adequate pathologic analysis.
Skin Examination- A complete skin examination is mandatory for
patients with suspected squamous cell carcinoma in situ. The
examination should be on both sun-exposed and non-exposed areas.
9. The symptoms of squamous cell carcinoma in situ are similar to those of other
diseases or conditions, so it is important not to mistake its symptoms.
Diseases that should be differentiated and ruled out to reach a conclusive
diagnosis of squamous cell carcinoma in situ include:
1. atopic dermatitis
2. pyoderma gangrenosum
3. Bowenoid papulosis
4. atypical fibroxanthoma
5. melanoma in situ
6. Paget disease.
10. Observation - As the risk of invasive SCC is low, it may not be necessary to remove all lesions,
particularly in elderly patients. Keratolytic emollients containing urea or salicylic acid may be
sufficient to improve symptoms.
Excision Solitary lesions can be cut out, and the defect repaired by stitching it up. Excision is
often recommended if there is suspicion of invasive SCC.
Superficial skin surgery- Superficial skin surgery refers to shave, curettage and electrosurgery,
and is an excellent choice for solitary or few hyperkeratotic lesions. The lesion is sliced off or
scraped out; then the base is cauterised. Dressings are applied to the open wound to encourage
moist wound healing over the next few weeks.
Cryotherapy- means removing a lesion by freezing it, usually with liquid nitrogen. Moderately
aggressive cryotherapy is suitable for multiple, small, flat patches of intraepidermal SCC. It
leaves a permanent white mark at the site of treatment.
Fluorouracil cream- 5-fluorouracil cream contains a cytotoxic agent and can be applied to
multiple lesions. The cream may be used for intraepidermal SCC for four weeks and repeated if
necessary. It causes a vigorous skin reaction that may ulcerate.
Imiquimod cream- Imiquimod cream is an immune response modifier used off-licence to treat
intraepidermal SCC. It is applied 3–5 times weekly for 4–16 weeks and causes
an inflammatory reaction.
11. Photodynamic therapy-
Photodynamic therapy (PDT) refers to treatment with a photosensitiser
(a porphyrin chemical) that is applied to the affected area before exposing it to a strong
source of visible light.
The treated area develops an inflammatory reaction and then heals over a couple of weeks or
so.
The best studied, methyl levulinate cream PDT used off licence, provides high cure rates for
intraepidermal SCC on the face or lower legs, with excellent cosmetic results.
The main disadvantage is the pain experienced by many patients during treatment.
Other treatments- occasionally used in the treatment of intraepidermal SCC include:
1. Combination treatments
2. Diclofenac gel
3. Topical retinoid (tazarotene, tretinoin)
4. Chemical peel
5. Radiotherapy
6. Electron beam therapy
7. Carbon dioxide laser ablation
8. Erbium:YAG laser ablation
