Risk factors associated with BBC include exposure to ultraviolent light, genetic factors, long term immunosuppression, and arsenic ingestion

A genetic predisposition for BCC is seen in several syndromes, such as nevoid basal cell carcinoma syndrome, may be transmitted to offspring.

BCC starts in the cells of the basal (deep) layer of the epidermis.UV exposure causes accumulation of genetic defects over time; lesion exhibits slow growth. Reported the most common form of skin cancer (approximately 80%)

Extraoral: Most found in head and neck area, classic lesion appears nodular with depressed center and rolled pearly borders often with capillaries seen throughout the border area. Intraoral: BCC rarely appears intraorally. It may appear on the lip of he vermillion border.

Treatment and prognosis: Surgical excision, laser surgery, cryosurgery (freezing with liquid nitrogen), electrodesiccation (burning), and radiation therapy. Radiation therapy for large tumors, those involving areas difficult to access, or other surgical problems such as tumors on the eyelids. The earlier these cancers are identified, the less invasive the procedures will have to be. The 5-year survival rate for localized BCC is over 99%. The median survival for metastatic BCC is 8 months. Patients who have had one skin cancer have a 50% chance of developing another BCC at a different site within 5 years. Patients should be monitored for new lesions on an annual basis for life.

Dental implication: when BCC is observed, the patient should be referred to an appropriate physician for evaluation.Refer for definitive diagnosis if lesion is suspicious through the patient history.

Causative agents: UV light, burned areas, genetics, and HPV

SCC associated with HPV occurs only after infection with the virus; otherwise it is not transmissible.

SCC is the second most common skin cancer (approximately 20%). It begins in keratinocytes of outer dermis, has a prolonged in situ stage, may metastasize in about 2% of cases

Extraoral: SCC usually develops in the preexisting actinic keratosis. Early SCC is usually painless, nonhealing, rough, red scaly papule that eventually becomes ulcerated and crusted as it enlarges and bleeds easily. Intraoral SCC are common.

Dental implications: lesions presenting as painless, nonhealing ulcers should be suspected as being SCC and should be biopsied.

Treatment and prognosis: surgical excision, laser surgery, cryosurgery (freezing with liquid nitrogen), electrodesiccation (burning), radiation therapy and photodynamic therapy (PDT), chemotherapy used to treat metastatic SCC, radiation therapy used for small tumors or to delay growth of large tumors or for areas where surgery is difficult or contraindicated.Early detection will mean less invasive treatment and better chance of complete elimination of cancer, patients who have had one skin cancer have a higher risk for another and should be monitored for new lesions on an annual basis. Prognosis—5-year survival rate for localized SCC is over 90%; metastatic 5-year survival rate drops to 25% to 45%.

Causation agents: UV radiation, Artificial tanning, Nevi/moles, Immunosuppression
, personal and/or family history of skin cancer and/or melanoma, Physical characteristics (fair skin, hair, etc.)
and History of blistering sunburns

Melanoma may be associated with a slight genetic predisposition.

Less than 1% of all skin cancers. Cause the majority of skin cancer deaths. Leading cause in women age 25 to 30. The second leading cause in women age 30 to 35. Most found in Caucasian men over age 50

Develops within melanocytes located deep in the basal layer of the epidermis or preexisting benign nevus (30%). Two stages of growth depending on the type of melanoma: horizontal—may not breach basement membrane for years and vertical—breaches the basement membrane and spreads to local and distant sites

Extraoral: Melanoma may present with a wide range of clinical characteristics, and many mimic the characteristic of benign pigmented lesions such as the nevus. May have a wide range of color possibilities: shades of brown and black, red, skin-colored or nonpigmented. Change in sensations: such as itching, numbness, tingling, etc.. Large flat multicolored macules. Firm dome-shaped shiny lesions.

Intraoral: 1% of all melanomas occur in mucosal surfaces including the oral cavity.

Dental Implication: The clinician should observe all visible pigmented areas using the ABCDE method and refer any suspicious areas for evaluation.

Treatment and prognosis: Surgery is treatment of choice with very large margins. All nodes in the area must be removes if even one node is involved.Radiation and chemotherapy are used to lengthen life and improve quality of life in those with distant metastasis.5-year survival rate 98%. In situ—98%. Regional lymph node involvement—62%. Distant metastasis—18%
Obviously, the earlier a melanoma is detected, the better the chances are for complete removal and recovery.

Delong, L & Burkhart, N. (2019). General and Oral Pathology for the Dental Hygienist. Third Edition. Philadelphia: Wolter Kluwer.