Clinical Diagnosis & Recent Trends in Management of Melanoma and malignant Keratinocytic tumors

Abstract

Human skin is considered the largest organ of the body. The surface area of the skin on an average adult is 1.8 m2, and represents 16% of the total body weight. It is divided into two main layers, the epidermis, dermis and skin appendages (hai follicles, seaceous and sweat glands. Several risk factors for malignant skin tumors are described; the most important of which is prolonged exposure of Ultraviolet rays (residing near the equator, ozone depletion areas, prolonged sun exposure, tanning beds). Other important risk factors as excessive exposure to ionizing radiation e.g: x-rays, Strong family history, Genetic skin diseases e.g: Gorlin's syndrome, xeroderma pigmentosa, or albinism. Also, burn scars & chronic ulcers, Premalignant skin lesions e.g: actinic keratosis and Bowen`s disease. Also, fairly skin ethnic groups & immunosuppressed patients and those with repeated contact to some chemical irritative substances. Keratinocytic tumors include; basal cell carcinoma (BCC), squamous cell carcinoma (SCC) &Bowen’s disease, while Melanocytic tumors include; superficial spreading melanoma, nodular melanoma, acral-lentiginous melanoma, amelanotic melanoma.

Early Detection of skin malignant tumors is held by both periodic clinical & self-examination of the skin, confirmatory diagnosis is done mainly by taking biopsy, tumor markers and radiological studies. Pathological examination of biopsies aids in determining the differentiation & hence the prognosis of the tumor. Other diagnostic tools, as nuclear medicine and dermatoscope, have important role in diagnosis, prognosis & assessing spread of malignant shin neoplasm. Treatment is dependent on specific type of cancer, location of the cancer, age of the patient, and whether the cancer is primary or a recurrence. Non-surgical management including; radiation therapy (external beam radiotherapy or brachytherapy), topical chemotherapy (imiquimod or 5-fluorouracil) and cryotherapy (freezing the cancer off) can provide adequate control of the disease; both, however, may have lower overall cure rates than certain types of surgery. Other modalities of treatment such as photodynamic therapy, topical chemotherapy, intralesional steroids, electrodesiccation and curettage can be found in the discussions of basal cell carcinoma and squamous cell carcinoma. Currently, surgical excision with safety margin is the most common & most successful form of treatment for skin cancers. It can be performed either by conventional excision with predetermined safety margin or by Moh’s micrographic surgery. The goal of reconstructive surgery is restoration of normal appearance and function. The choice of technique in reconstruction is dictated by the size and location of the defect. Excision and reconstruction of facial skin cancers is generally more challenging due to the presence of highly visible and functional anatomic structures in the face. When skin defects are small in size, most can be repaired with simple repair where skin edges are approximated and closed with sutures making a linear scar. Larger defects may require repair with a skin graft (split or full thickness), local, regional or distant flap, or a microvascular free flap.