Skin Cancers

 

BASAL CELL CARCINOMA

Basal cell carcinoma ( BCC) is the most common type of skin cancer. This malignant tumor is locally invasive, aggressive, and destructive, but there is a limited capacity to metastasize. The reason for this characteristic is the tumor’s growth dependency on its stroma, which on invasion of tumor cells into the vessels is not disseminated with the tumor cells. When tumor cells lodge at distant sites, they do not multiply and grow because of the absence of growth factors derived from the stroma of the tumor. Exceptions occur when a BCC rarely occur on the vermilion border of the lips or on the genital mucous membranes.

Most lesions are readily controlled by various surgical techniques or cryotherapy. Serious problems, however, may occur with BCC arising in certain locations on the face: around the eyes, in the nasolabial folds, around the ear canal, or in the posterior auricular sulcus. In these sites the tumor may invade deeply, cause extensive destructions of muscle and bone.

EPIDEMIOLOGY

  • Age of Onset    Older than 40 years.
  • Sex    Males more than females
  • Race Rare in brown – and black-skinned persons
  • Predisposing Factors White –skinned persons with poor tanning capacity (skin phototypes I and II) and albinos are highly susceptible to develop BCC with prolonged sun exposure. Previous therapy with x-rays for facial acne greatly increases the risk of BCC, even in those persons with a good ability to tan (skin phototypes III and Iv).

PHYSICAL EXAMINATION

Four clinical type Nodular, ulcerating, sclerosing (cicatricial), superficial, pigmented.

  • Nodular Papule or nodule, translucent or ‘pearly’
  • Ulcerating Ulcer (often covered with a crust) with a rolled border (rodent ulcer)
  • Sclerosing orCicatricial BCCs appear as scars
  • Pigmented

MANAGEMENT

  • Topical Chemotherapy 5-fluorouracil cream applied qd or bid with or without tape occlusion is effective in some cases arising in the trunk or extremities.
  • Cryosurgery Effective in some cases. Lesions are usually treated more aggressively than solar keratoses and less aggressively than basal cell carcinoma.
  • Surgical Excision Has the highest cure rate but the greatest chance of causing cosmetically disfiguring scars

SQUAMOUS CELL CARCINOMA IN SITU

Squamous cell carcinoma in situ (SCCIS) is most often caused by ultraviolet radiation (UVR) or human papillomavirus (HPV) infection, presenting as a solitary or multiple macules, papules, or plaques, which may de scaling or hyperkeratotic. SCCIS commonly arises in epithelial dysplastic lesions such as keratoses or HPV-induced squamous intraepithelial lesions (SIL).

Synonyms:  these lesions have various associated eponyms such as Bowen’s disease or erythroplasia of Queyrat. While terms such as UVR- or HPV-associated SCCIS are more meaningful to all specialties of medicine, Bowen’s disease erythroplasia are well defined morphological entities and thus helpful to the dermatologist.

EPIDEMIOLOGY

  • Age of Onset    Older than 40 years.
  • Sex    Males more than females
  • Race Rare in brown – and black-skinned persons
  • Predisposing Factors White –skinned persons with poor tanning capacity (skin phototypes I and II) and albinos are highly susceptible to develop BCC with prolonged sun exposure. Previous therapy with x-rays for facial acne greatly increases the risk of BCC, even in those persons with a good ability to tan (skin phototypes III and Iv).

ETIOLOGY

UVR, HPV, arsenic, tar, chronic heat exposure, chronic radiation dermatitis, scar.

HISTORY

Lesions are most often asymptomatic, but may bleed. Nodule formation within SCCIS suggests progression to invasive SCC.

PHYSICAL EXAMINATION

  • Skin Findings Appears as a sharply demarcated, scaling, or hyperkeratotic macule, papule, or plaque. Solitary or multiple lesions are often pink or red in color and have a slightly scaling surface, small erosions, and can be crusted. Such lesions are always well-defined and are called Bowen’s disease.
  • Distribution SCCIS commonly arise within a solar keratosis in the setting of photoaging (dermatoheliosis).
  • Associated Findings Depending on the etiology, dermatoheliosis, actinic keratoses, condyloma acuminatum, SIL, poikiloderma congenital, epidermal nevus, porokeratosis, epidemodysplasia verruciformis.

COURSE AND PROGNOSIS

Untreated, invasive SCC may arise within SCCIS. Lymph node metastasis can occur without demonstrable invasion. SCCIS associated with arsenic ingestion may be associated with internal malignancies.

MANAGEMENT

  • Topical Chemotherapy 5-fluorouracil cream applied qd or bid with or without tape occlusion is effective in some cases arising in the trunk or extremities.
  • Cryosurgery Effective in some cases. Lesions are usually treated more aggressively than solar keratoses and less aggressively than basal cell carcinoma.
  • Surgical Excision Has the highest cure rate but the greatest chance of causing cosmetically disfiguring scars.

INVASIVE SQUAMOUS CELL CARCINOMA

Invasive squamous cell carcinoma (SCC) is a malignant tumor of keratinocytes, arising in the epidermis, skin appendages, and stratified squamous mucosa. In contrast to basal cell carcinoma (BCC), invasive SCC usually arises in epidermal precancerous lesions. More aggressive SCC occur in immunosuppressed individuals with a greater incidence of metastasis. Treatment of precursor lesions prevents invasive SCC.

EPIDEMIOLOGY

  • Age of Onset    Older than 40 years.
  • Sex    Males more than females
  • Race Rare in brown – and black-skinned persons
  • Predisposing Factors White –skinned persons with poor tanning capacity (skin phototypes I and II) and albinos are highly susceptible to develop BCC with prolonged sun exposure. Previous therapy with x-rays for facial acne greatly increases the risk of SCC, even in those persons with a good ability to tan (skin phototypes III and Iv).

ETIOLOGY

  • Ultraviolet Radiation
  • Age of Onset Older than 55 years of age in the United States; in Australia and New  Zealand, in the twenties and thirties.
  • Sex Males > females, but SCC can occur more frequently  on the legs  of females.
  • Exposure Sunlight .Phototherapy with oral PUVA ( oral psoralen  + UVA). Photochemotherapy cal lead to promotion of SCC in patients who have had an excessive number of PUVA treatments sessions , or a history of previous exposure to ionizing radiation ( electron beam, grenz rays) or history of methotrexate treatment for psoriasis.
  • Incidence Continental United States: 12 per 100,000 white males; 7 per 100,000 white females. Hawaii: 62 per 100,000 whites.
  • Race Persons with white skin and poor tanning capacity ( skin photypes I and II ) ( see Section 8). Brown- or black-skinned persons can develop SCC from numerous etiologic agents other than the UVR.
  • Geography Most common in areas that have many days of sunshine annually, i.e., in Australia and southwestern United States.
  • Occupation Persons working outdoors- farmers, sailors, lifeguards, telephone line installers, construction workers, dock workers.
  • Human Papillomavirus Oncogenic HPV type-16, -18, -31, -33, -35, -45 etc, are associated with epithelial dysplasia, SCC in situ ( SCCIS ), and invasive SCC.
  • Immunosupression Solid organ transplant recipients, individuals with chronic immunosuppression of inflammatory disorders, and those with HIV disease are associated with an increased incidence of invasive SCCs.
  • Chronic Inflammation Chronic cutaneous lupus erythematosus, chronic ulcers, burn scars, chronic radiation dermatitis.
  •  Industrial Carcinogens Pitsch, tar, crude paraffin oil, creosote, lubricating oil, nitrosoureas.

 HISTORY

Slowly evolving-any isolated keratotic papule or plaque or nodule with an ulcer in a suspect patient that perisists for over a month  is considered a carcinoma until proved otherwise. Note that SCC is usually asymptomatic.  

MANAGEMENT

  • Surgery Depending on localization  and extent of lesion, excision with primary closure, skin flaps, or grafting.
  • Lymph node dissections
  • Radiotherapy should be performed as an adjuvant therapy to surgery or if surgery is not feasible.
  • Immunotherapy / Chemotherapy in selected cases along with surgery or in relapsed cases

COURSE AND PROGNOSIS

SCC has an overall remission rate after therapy of 90%. Those tumors which are induced by ionizing radiation, or following inorganic trivalent arsenic, or in an old burn scar, or on the lip or genitalia, are more likely to metastasize. SCC in the skin has an overall metastatic rate of 3 to 4%, with those lesions arising in solar keratoses having the lowest potentiol  for metastasis. Cancers arising in chronic osteomeyelitis sinus tracts and in burn scars and sites of radiation dermatitis  have a much higher  metastatic rate ( 31, 20 and 18%, respectively).

MELANOMA

EPIDEMIOLOGY

Melanoma is the fifth most common cancer diagnosed in the United States, and the number of new cases has risen significantly since the early 1990s.

According to the National Cancer Institute, an estimated 106,110 people in the United States will be diagnosed with melanoma in 2021. Melanoma is less common than some other types of skin cancer, but it’s more likely to grow and spread.

CAUSES

Melanoma develops when pigment-producing cells known as melanocytes mutate. Although most melanocytes are found in the skin, some occur in the eyes and other parts of the body. Though the exact cause of melanoma isn’t always clear, the primary risk factor is exposure to ultraviolet radiation from the sun or tanning beds. People who have had frequent sunburns, especially as children, have an increased risk.

Learn more about risk factors for melanoma

MELANOMA TYPES

The most common type of melanoma is cutaneous, which develops on the skin. While most melanomas develop on skin exposed to the sun, the disease may also be found in areas not exposed, such as the groin or the bottoms of the feet, the eye or even the gut.

Other types of melanoma include:

  • Superficial spreading melanoma
  • Nodular melanoma
  • Acral-lentiginous melanoma
  • Lentigo maligna melanoma
  • Amelanotic and desmoplastic melanomas
  • Ocular melanoma

Melanoma that has spread to distant organs is called metastatic melanoma. The disease most often spreads to the lungs, liver, bone and/or brain.

SYMPTOMS

Most melanomas develop on the skin, where they may be detected early. Regular skin examinations, either self-exams or those performed by a doctor, can help spot suspicious moles or changes in the skin that may be early signs of melanoma.

Other symptoms include:

  • Wounds that don’t heal
  • Redness, swelling or tender skin
  • Oozing or bleeding from a mole
  • Dark spots in the eyes, loss of sight or blurry vision

DIAGNOSIS

Diagnosing melanoma begins with a visual examination. If a suspicious mole is found, a doctor may remove it and send a sample to the laboratory to determine if it is melanoma, some other form skin cancer or a benign growth. If melanoma is found, more extensive surgery may be required to completely remove the tumor and surrounding tissue. Further examinations may be used to determine if the melanoma has spread to nearby lymph nodes or distant organs.

Evaluation and staging includes:

  • Biopsies
  • MRI / CT scan
  • Pet Scan

TREATMENT

  • Surgery is the primary treatment for localized melanoma and may be an option if the disease has spread and formed tumors in distant organs. Surgeries to treat melanoma may include:
  • Excision to remove the tumor and surrounding tissue
  • Reconstructive surgery to reduce scarring or disfigurement, especially if the cancer is found on the face or other exposed areas
  • Lymph node removal to determine if the cancer has spread into the lymph system
  • Surgery for metastatic melanoma to remove melanoma tumors that have formed in the liver, lungs, brain or other organs

Other treatments for melanoma include: