Skin neoplasms, are skin growths with differing causes and varying degrees of malignancy. Malignant skin cancer is named after the type of skin cell it arises from. Skin cancer generally develops in the epidermis.
CLASSIFICATIONThere are three main types of skin cancer: Basal cell carcinoma (BCC), Squamous cell carcinoma(SCC) Malignant melanoma
BASAL-CELL CARCINOMA The most common type of skin cancer. It rarely metastasizes or kills. Because it can cause significant destruction and disfigurement by invading surrounding tissues it is consider as malignant.
SIGNS AND SYMPTOMSPresent as A shiny, pearly nodule. A red patch like eczema. A skin thickening or scar tissue.
DISTRIBUTION Two thirds of basal-cell carcinomas occur on sun-exposed areas of the body. One-third occur on areas of the body that are not exposed to sunlight, emphasizing the genetic susceptibility of basal-cell cancer patients.
DIAGNOSIS Skin biopsy. Common method is a shave biopsy under local anesthesia.
PATHOPHYSIOLOGY Basal cell Ca develop in the basal cell layer of the skin. Sun light exposure leads to the formation of thymine dimers, a form of DNA damage. DNA repair removes most UV-induced damage, not all crosslinks are excised. Cumulative DNA damage leads to mutations. Apart from the mutagenesis, sunlight depresses the local immune system, decreasing immune surveillance for new tumor cells. Basal-cell carcinoma also develops as a result of Basal-Cell Nevus Syndrome.
PREVENTION Sun screens with at least SPF 30. Use of a chemotherapeutic agent such as 5- Fluorouracil can prevent development of skin cancer. It is usually recommended to individuals with extensive sun damage, history of multiple skin cancers, or precancerous growths
TREATMENT Standard surgical excision Chemotherapy Immunotherapy Radiation Photodynamic therapy Cryosurgery Electrodesiccation and curettage
PROGNOSIS Prognosis is excellent if the appropriate method of treatment is used in early primary basal-cell cancers. Recurrent cancers are harder to cure, with any methods of treatment.
SQUAMOUS-CELL CARCINOMAA histologically distinct form of cancer. It arises from the uncontrolled multiplication of malignant cells deriving from epithelium, or showing particular cytological or tissue architectural characteristics of squamous cell differentiation, such as the presence of keratin.
SIGNS AND SYMPTOMS The lesion caused by SCC is often asymptomatic Ulcer or reddish skin plaque that is slow growing Intermittent bleeding from the tumor Usually the tumor presents as an ulcerated lesion with hard, raised edges The tumor may be in the form of a hard plaque or a papule. The tumor commonly presents on sun-exposed areas (e.g. back of the hand, scalp, lip, and superior surface of pinna Evidence of chronic skin photodamage, such as multiple actinic keratoses. Unlike basal cell carcinoma (BCC), squamous cell carcinoma (SCC) has a substantial risk of metastasis. Risk of metastasis is higher in SCC arising in scars, on the lower lips or mucosa, and occurring in immunosuppressed patients. About one-third of lingual and mucosal tumors metastasize before diagnosis (these are often related to tobacco and alcohol use)
CAUSES Human papilloma virus has been associated with SqCC of the oropharynx, lung, fingers, and anogenital region. Sunlight exposure and immunosuppression are risk factor for SCC of the skin. Bladder cancer associated with Schistosomiasis is often squamous cell carcinoma.
PREVENTION Appropriate clothing. Avoidance of intense sun exposure Avoidance of sunscreen may prevent skin cancer.
MANAGEMENT Surgical excision with a free margin of healthy tissue is a frequent treatment modality. Radiotherapy, given as external beam radiotherapy or as brachytherapy (internal radiotherapy), can also be used to treat squamous cell carcinomas. A few selected cases are treated with topical medication.
MELANOMA A malignant tumor of melanocytes. Melanoma is less common than other skin cancers.
SIGNS AND SYMPTOMS Asymmetry Borders (irregular) Color (variegated), and Diameter (greater than 6 mm) Evolving over time
CAUSE All cancers are caused by damage to the DNA inside cells. This damage can be inherited in the form of genetic mutations. In most cases, damage builds up over a persons lifetime and is caused by factors in their environment UV radiation
DIAGNOSIS Visual diagnosis of melanomas is still the most common method employed by health professionals. Biopsy of the suspicious mole.
PREVENTION Minimizing exposure to sources of ultraviolet radiation
TREATMENT Wider excision of the scar or tumor. Depending on the stage, a sentinel lymph node biopsy is done. Adjuvant treatment Chemotherapy and immunotherapy
PROGNOSISFeatures that affect prognosis are: Tumor thickness in millimeters (Breslows depth) Depth related to skin structures (Clark level), Type of melanoma Presence of ulceration, presence of lymphatic/ perineural invasion, Presence of tumor-infiltrating lymphocytes Location of lesion, Presence of satellite lesions. Presence of regional or distant metastasis.