Skin tumors

Malignant skin tumors

Is subdivided into non-melanoma skin cancer (includes basal cell carcinoma and squamous cell carcinoma) and malignant melanoma
Basal Cell Carcinoma (BCC)
The most common skin cancer in human
BCC occurs most frequently on the head and neck
Mortality from BCC is quite rare
Types of BCC
Nodular BCC: is one type of BCC and is the most common type, present as a translucent papule or nodule with telangiectasia , sometimes with a central depression or ulcer surrounded by a rolled edge.
Squamous Cell Carcinoma (SCC)
The majority of SCC occurs on the head, neck and upper extremities and present as an erythematous scaly papule or nodule
While melanoma among whites is responsible for 90% of skin cancer deaths before 50 years of age, in adults over 50 years of age, the majority of skin cancer deaths are attributable to SCC
Risk factors:
Environmentl: Sun exposure, ionizing radiation, chemicals e.g. tar, arsenic and, HPV, burn, chronic ulcer and scar (Marjolin's ulcer)
Genetic: xeroderma pigmentosum and oculocutaneous albinism
Immunological: immunosuppressive drugs, organ transplant recipients, HIV
Treatment of BCC and SCC:
1. Surgical excision
2. Electrodesiccation and curettage
3. Mohs(microscopic) Surgery: has the highest cure rate, used when tissue preservation is necessary e.g. digits, genitalia
Medical therapy : 5-fluorouracil,
Radiotherapy: elderly patient unfit for surgery
Cryotherapy (by freezing)


Malignant Melanoma (MM)
Malignancy arising from melanocytes.
Death from melanoma occurs at a younger age than from other solid tumors
Melanoma incidence in Australia is the highest worldwide
Types:
1. Superficial spreading melanoma: the most common type of MM in fair-skinned persons, on leg of female and trunk of male
3. Acral lentignious melanoma: occur on palm, sole and nail , commonly occur in black and Asians

Staging:

Stage I: skin only ( up to 2 mm thick)
Stage II: skin only (more than 2 mm thick)
Stage III: Regional lymph nodes metastasis
Stage: IV: non-regional LN metastasis and visceral metastasis
Diagnosis:
Hx: The criteria in Hx that make us suspect MM: family or personal Hx of melanoma, Hx of childhood sunburn , HIV or organ transplant, , change in color, size, shape, bleeding , ulceration, itching
Examination: The criteria in exam that make us suspect MM: large no. of nevi, presence atypical nevi which must have one of ABCDE ( A: asymmetry, B: irregular border, C: color variegation, D: diameter more than 6 mm, E: evolution)
Investigation: Excisional biopsy +/- Dermoscopy
Treatment:
Stage I/II : wide local excision of the lesion with safety margin
Stage III: Sentinel lymph node biopsy (if positive, then LN dissection is necessary plus adjuvant therapy )
Stage IV: Palliative Rx ( improve quality of life) which includes: RadioRx, chemoRx and immunoRx e.g. BCG


Benign skin tumors
Epidermoid cyst
The most common cutaneous cysts. Most commonly develop on the face and upper trunk
Present as a dermal nodules, may have a central punctum representing the follicle from which the cyst is derived
Multiple epidermoid cysts may occur in individuals with a history of significant acne vulgaris and Gardner syndrome
They are asymptomatic, but, with pressure, cysts contents may be expressed that have a malodor
Rupture of the cyst wall can result in an intensely painful foreign body inflammatory reaction, and this is a common reason for presentation
Treatment: Excision is curative
Milium
Are small epidermoid cysts
Present as 1–2 mm white to yellow papules
May occur as a primary, or secondary following(1) blistering diseases such as porphyria (2) erosion from cosmetic procedures e.g. dermabrasion or (3) topical treatment e.g. steroids
Treatment:
Most milia in newborns will resolve spontaneously
Incising the overlying epidermis and expressing the milium or Electrodesiccation
Hypertrophic scar and keloid
Result from the uncontrolled synthesis and excessive deposition of collagen at sites of prior skin injury
More in darkly pigmented the skin and there is often a familial tendency
Especially frequent on the earlobes, upper trunk, and the deltoid region (areas of high tension)
Melanocytes and mast cells are believed to contribute to the pathogenesis
Treatment: includes
Surgery(high rate of recurrence), intralesional corticosteroids, intralesional 5-Fluorouracil, topical silicone gel sheeting


Skin tags
Presents as a soft pedunculated papule, usually asymptomatic
Predominantly on the neck, eyelid, axilla and groin
Their incidence increases with age and more commonly seen in obese individuals
Larger lesions may be associated with diabetes mellitus
Treatment: simple scissor excision, electrodesiccation or cryoRx
Actinic keratois(AK)
Actinic keratoses (AK) are premalignant lesions and SCC would develop at a rate of 10-20%
They present on sun-exposed skin of the head, neck, and extremities
Actinic cheilitis : AK involving lower lip

Acquired melanocytic nevus

Caucasians in general have greater numbers of nevi than do darker-skinned
One-third of melanomas are associated with nevi
An increased number of melanocytic nevi marks increased melanoma risk.
The most important DDx is melanoma and atypical nevus which is characterized by ( ABCDE, A: Asymmetry, B: Irregular Border, C: Variegated Color, D: Diameter more than 6 mm, E: Evolving which mean any change in color, size or shape)
There are three types:
Junctional nevi are a macules. Histologically: nests of melanocytes at the junction between the epidermis and dermis
Compound nevi with nests of melanocytes in both dermis and junction
Dermal nevi are papules with nests in dermis
Congenital melanocytic nevus
Present at birth
There are three types; small (less than 1.5 cm in diameter), medium (1.5-19.9 cm) and large or giant (more than 20 cm)
There is a significant risk of development of melanoma of skin and meninges in patient with giant nevus