Introduction
The basal cell carcinoma is the most common tumor in the world. It is a tumour that originates from the basal cell layer of the skin. Stressful factors for a basal cell carcinoma are white skin, UV-radiation and a high age, this is to be justified with the increase of UV-exposure with increasing age.
Further influencing factors are chemical noxae and genetic predispositions. In Germany, an average of 130000 people are diagnosed with basal cell carcinoma per year. Women and men are equally affected. The average age of the disease is about 60 years, although the patients have become younger in recent years. Due to the low risk of metastasis and the very rare fatal courses, the basal cell carcinoma is one of the ‘semi-malignant’ tumours.
Forms of the basal cell carcinoma
A large number of different forms of basal cell carcinoma can be distinguished. Based on the histological differentiation and composition of the cells, the WHO currently distinguishes the following subtypes: Multifocal superficial basal cell carcinoma (superficially multicentric) Solid nodular basal cell carcinoma Adenoidal nodular basal cell carcinoma Cystic nodular basal cell carcinoma Infiltrative basal cell carcinoma, non-sclerosing, sclerosing (desmoplastic, morphea-like) Fibroepithelial basal cell carcinoma Basal cell carcinoma with adnexoid differentiation, follicular, eccrine Basosquamous carcinoma Keratotic basal cell carcinoma Pigmented basal cell carcinoma Basal cell carcinoma in basal cell nevus syndrome Micronodular basal cell carcinoma The individual subtypes show different forms of growth. Superficial tumours are less prone to infiltrative growth than ulcerative ones.
In practice, however, mixed forms are also frequently encountered. It is very difficult for a layman to classify the individual forms of the disease. – Multifocal superficial basal cell carcinoma (superficial multicenter)
- Solid nodular basal cell carcinoma
- Adenoidal nodular basal cell carcinoma
- Cystic nodular basal cell carcinoma
- Infiltrative basal cell carcinoma, non-sclerosing, sclerosing (desmoplastic, morphea-like)
- Fibroepithelial basal cell carcinoma
- Basal cell carcinoma with adnexoid differentiation, follicular, eccrine
- Basosquamous carcinoma
- Keratotic basal cell carcinoma
- Pigmented basal cell carcinoma
- Basal cell carcinoma in basal cell nevus syndrome
- Micronodular basal cell carcinoma
Staging of the basal cell carcinoma
In general, according to the WHO, the UICC classification applies to basaliomas and their stages. This means that the prognosis and therapy is based on the criteria of size, lymph node metastases and distant metastases. However, as the basal cell carcinoma only metastasizes in 1:1000 cases, as mentioned above, this classification is useless in practice. The intended therapy is usually always a total resection of the basal cell carcinoma. To estimate the extent of resection and a possible therapy, the following assessment criteria are used in current practice:
- Clinical tumor size (horizontal tumor diameter)
- Localization
- Basal cell type
- Histological depth extension (vertical tumor diameter)
- Therapeutic safety distance (for resection)
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