Skin tumors
They can be benign or malignant. Benign tumors like viral warts, melanocytic nevi, milia, epidermal cysts, haemangioma, pyogenic granuloma or dermatofibroma.
  Malignant skin tumors:
 Aetiology:
1.	Genetic factors: Xeroderma pigmentosum, neurofibroma may change to neurofibrosarcoma.
2.	Environmental factors:
a-	Ultraviolet light is the most important factor especially in those with fair skin.
b-	Tar, arsenic, mineral oils.
c-	X-ray: diagnostic or therapeutic.
d-	Long standing scars, fistulas, sinuses.
e-	Viruses: Burkuit lymphoma ----------- EBV
                   HPV may cause Ca cervix
                 Kaposi sarcoma is thought to be caused by herpes simplex virus-8.
f-	Drugs: long lasting use of immunosuppressant like azathioprime, cyclophosphamide, cyclosporine or even steroids.

Premalignant skin diseases:
    A group of diseases that have a potential to change into malignant disorder:
1.	Actinic or solar keratosis may change to squamous cell carcinoma in 20% of the cases. Actinic cheilitis has the same probability.
2.	Bowen, s disease: intraepidemal carcinoma with dysplastic changes limited to the epidermis also may change to sq. cell ca.
3.	Chronic scars: burn, lupus vulgaris, DLE.
4.	Dysplastic nevi and large congenital nevus may change into malignant melanoma.
5.	Chronic keratosis like those induced by tar, arsenic, X-radiation or infrared radiation.
6.	Leukoplakia of the mucous membranes.
7.	Disseminated superficial actinic porokeratosis.  

Seborrhoeic keratosis:
It is a common benign epidermal tumor that affects mainly the middle aged and elderly people and occurs more commonly in males.
  The lesions are usually asymptomatic. It arises as flesh colored or pigmented patch, plaque, or nodule that have a characteristic stuck-on appearance. The surface is usually rough and the lesions usually flat but sometimes pedunculated. They can be single but usually multiple and arise on the face and upper trunk.
The sign of Leser-Telat: is a skin disorder characterized by the abrupt appearance of multiple seborrhoeic keratoses that rapidly increase in their size and number. It is caused by an associated cancer.
Treatment: reassurance if the lesions found in hidden sites. If the patients want to remove the lesion due to cosmetic reasons we can remove them by curettage, cautery, cryotherapy or laser.

Actinic (solar) keratosis:
   It is a common premalignant skin condition that may change into sq. cell ca. in 20 % of the cases. They arise in old patient on the sun-exposed areas like face, scalp, ears and dorsum of the hands. They arise as ill-defined erythematosus lesions covered with thick verrocous surface.
Treatment:
 In solitary or few lesions- remove the lesions by surgery, cryotherapy, electrocautery or laser.
  In multiple lesions we can use topical chemotherapy with 5- fluorouracil and imiquimod.
                         
          Malignant epidermal tumors

BASAL CELL CARCINOMA
 It is the most common form of skin malignancy. Although the lesions may extend locally to invade deeper structures like cartilage or bone, they practically never or very rarely metastasize.
The disease induced mainly by chronic sun-exposure, and it is seen mainly in outdoor workers. It occurs mainly in old people and seen more commonly on the face.
Clinical types:
1.	Noduloulcerative (Rodent ulcer): it is the most common type that starts as small skin colored glistening translucent papule. The lesion enlarged very slowly over months or years.  Central necrosis may occurs leading to an ulcer covered by adherent crust with a well demarcated rolled pearly beaded border crossed by fine telangiectasia.
2.	Cystic type: the necrosis doesn’t occur here and the tumor gradually becomes cystic with prominent telangiectasia.
3.	Cicatricial (Morphoeic) BCC:  The patient has ill defined white plaque with sometimes small pearly border. This type carry poor prognosis with high recurrence rate after treatment.
4.	Superficial spreading BCC: this is very slowly progressive type that may reach large size with very thin thread like border. It is most commonly seen on the trunk.
5.	Pigmented BCC: very prominent pigmentation. It may occur with any of the previous forms.
Treatment: the prognosis is generally good. The type of treatment depends on the site, size of the lesion and the age, general health and cosmetic appearance of the patient.
1.	Excision of the lesion is the treatment of choice in patients under 60. Mohs, micrographic surgery is a microscopically controlled technique that may be preserved for high risk types or recurrent tumors.
2.	curettage and cautery
3.	Cryotherapy for small lesions.
4.	Topical chemotherapy like 5-flurouracil and 5% Imiquimod cream. The latter is an immune response modifier that induces cytokines related to cell mediated immune responses.
5.	Radiotherapy when surgery is contraindicated in elderly or diseased patient or when the surgery is very difficult e.g. nears the eye. 

Squamous cell carcinoma:
   It is less common but more aggressive than BCC and it is metastasized at early stages to the adjacent lymph nodes and rarely to distant sites.
   It is mainly induced by chronic sun exposure and it occurs mainly on sun exposed areas, but a good percentage of the cases may arise on underlying unhealthy skin or at the site of premalignant conditions.
The lesion arise as small nodule that enlarge, relatively more rapid than BCC, and break down into ulcer with characteristic indurated base. The lesions most commonly arise on the face, lower lip, outer border of the ear, scalp and dorsa of the hands.
Treatment: surgical excision with 0.5 cm safe margin, radiotherapy in inoperable lesions or in elderly.

Malignant melanoma:
   It is a highly malignant and usually lethal but fortunately, it is rare in Iraq. The incidence of the disease is doubled every 10 years in USA, Australia  and UK.
Aetiology:
1.	Genetic: it is more likely to occur in whites with blond hair and fair skin.
2.	Sunlight: tumors occur most commonly on sun exposed area with history of excessive sun exposure.
3.	Pre-existed melanocytic nevi: It may occur in any melanocytic nevus but the incidence of malignant changes highest in those with giant congenital nevi or dysplastic nevi i.e. nevi with irregular shape and color. Preexisting nevus is seen in about 30% of cases of malignant melanoma.

Signs of malignant transformation in melanocytic nevus:
1.	sudden enlargement of the lesion
2.	Irregularity of the shape, border and surface of the lesion.
3.	Variation in the color of the lesion i.e. variegated color.
4.	The lesion become symptomatic i.e. itching, pain, tenderness
5.	Signs of inflammation i.e. erythema, swelling and tenderness
6.	ulceration 
7.	Bleeding in advanced cases.

Clinical features:
1.	Lentigo maligna melanoma: it is occur on the sun exposed areas especially on the face. It arises as very slowly, over few years, growing irregularly shaped and pigmented patch. Malignant stage appears as indurated nodules followed by ulceration and bleeding.
2.	Superficial spreading melanoma: These lesions occur mainly on the legs of females and trunk of males between the 3rd and 5th decades of life. They grow radially or horizontally in early stages. The vertical growth indicate malignant stage and appear clinically as irregularly shaped patch with different colors –variegated color- with black deep indurated nodules.
3.	Acral lentiginous melanoma: This is the main type seen in Iraq. The lesions arise mainly on the palms, soles, fingers or the nail. It is the most dangerous type of the disease as it is often neglected by the patient or even the physician, leading to delayed diagnosis. They arise as pigmented lesions on the palms and soles that may end with early lymph node metastases. 
4.	Nodular melanoma: This the most aggressive type of the tumor and usually arise de novo i.e. without preexisting lesion. It arises as rapidly enlarged pigmented nodule with or without ulceration and bleeding.
Treatment:
-	Surgical excision with wide safe margin of normal skin around the lesion.
-	Palliative treatment for unresectable tumor as chemotherapy or radiotherapy.
-	En-block dissection of the tumor and the affected lymph nodes.

Cutaneous T-cell Lymphoma (Mycosis fungoides)
  A slowly growing tumor of the skin associated T-helper lymphocytes. It affects mainly the middle aged and elderly people and affect male more commonly than females. The disease passes usually through three stages although the disease may present or persisted in any stage:
1. Premycotic patch stage - poikiloderma: this stage may last for few years and presented as severely itchy non specific erythematosus patch with sharp demarcation and bizarre shape. 
   Poikiloderma referred to combination of atrophy, hypo and hyperpigmentation of the skin with telangiectasia and it may be the presenting feature of the disease.
2. Plaque stage: the lesions become palpable with infiltrated and indurated base due to deeper invasion.
3. Tumor stage: This stage may occur after many years of the onset of the disease as deep and large ulcerating or fungating tumor and it represent an advanced stage of the disease. Metastases to the lymph nodes and visceral organs may occur.
Sezary syndrome: It is the leucaemic phase of mycosis fungoides and characterized by severe itching, erythroderma, palpable lymph nodes and presence of atypical malignant cells in the peripheral blood of the patient.

Histopathology: Atypical lymphocytes within the dense inflammatory lymphocytic infiltrate that located mainly in the upper dermis in direct contact with the epidermis. Some of these atypical lymphocytes may invade the epidermis and form small collections inside the epidermis called Pauterier microabscesses
Treatment:
1.	Potent topical steroids to relieve itching.
2.	Topical cytotoxic like nitrogen mustard (Mechlorethamine).
3.	PUVA and UVB
4.	Radiotherapy in tumor stage
5.	Systemic chemotherapy