Squamous Cell Carcinoma
See also the article on precancerous lesions preceding squamous cell carcinoma Precancerous Lesions Preceding Squamous Cell Carcinoma (Actinic Keratosis and Carcinoma in Situ, or Bowen's Disease).
Essentials
- Squamous cell carcinoma (SCC, epidermoid/spinocellular/squamocellular carcinoma) develops from the epidermal cells as a result of long term exposure to UV radiation.
- It may metastasise to nearby lymph nodes.
- SCC may arise directly on healthy looking skin, but more frequently it develops on a precancerous lesion, such as:
- SCC is always treated surgically in specialized care.
- Immunosuppressive therapy lasting for several years, e.g. in organ transplant recipients, predisposes the patient to SCC.
Diagnosis
- SCC is usually a clearly demarcated, reddish or skin-coloured nodule frequently with a hyperkeratotic and ulcerated surface (Image 4).
- No telangiectasias are present on the surface as is the case in typical basal cell carcinoma (BCC) Basal Cell Carcinoma.
- SCC is often a rapidly growing and partly ulcerated skin tumour on areas of skin unprotected against the sun, such as the face, the backs of the hands or lower legs.
- The final diagnosis is histological.
- The risk of metastasis depends on:
- tumour-related risk factors, such as location in a risk area (ear lobe, lip, scalp), large size, thickness, rapid growth, histological type
- patient-related risk factors, such as immunosuppressive medication, history of radiotherapy to or chronic inflammation of the tumour area.
- Keratoacanthoma is a rapidly growing well differentiated SCC (Images 5 6 7).
Treatment
- SCC is treated surgically in specialized care.
- There should be at least a 5-mm margin of healthy tissue (a histological margin of at least 2 mm).
- In cases with a high risk of recurrence, wider surgical margins are recommended.
- Examinations to exclude metastasis to lymph nodes (imaging, sentinel lymph nodes) should be performed on a case by case basis.
- The frequency and length of follow-up is determined by the risk of recurrence and the stage of the tumour.
- Keratoacanthoma is a SCC with low risk of recurrence. A 5-mm margin of healthy tissue should be aimed at in its removal.
Specialist consultation
- If SCC is diagnosed by skin biopsy or excision of a skin lesion in primary health care, the patient should be referred to specialized care.
SCC of the lip
- Most commonly encountered on the lower lip (Images 8 9).
- Starts as a sore or ulcer usually preceded by actinic cheilitis or leukoplakia.
- Lip cancer is managed surgically in specialized care by excising the tumour with adequate margins followed by a reconstruction.
- Lip cancer may metastasise to the lymph nodes under the lower jaw, and these should be palpated at follow-up examinations.