Tumor and lesions of the skin

Squamous Cell Carcinoma

Squamous Cell Carcinoma (SCC) of the skin is a tumor of the epidermal keratinocytes which in its intraepidermal form is an incomplete carcinoma but which in its invasive form has the characteristics of malignant tumors; the most important of these are anaplasia, rapid growth rate, invasion of local tissues, and ability to metastasize.

Basal Cell Carcinoma

Basal Cell Carcinoma (BCC) is a malignant epithelial tumor of the skin that arises from basal cells of the epidermis and its appendages.

Its cellular components resemble the relatively undifferential, immature cells of the basal layer, and it requires a characteristic stroma. It rarely metastasizes.

Other synonyms include basalioma and ulcus rodens.

Treatment

Medical care: the treatment of BCC and SCC is surgical. Chemotherapy does not play a role in management. In patients with unresectable tumors, radiotherapy may be attempted as palliative treatment. Radiotherapy may be considered for advanced tumors as an adjuvant to surgery or in selected patients with early tumors as a definitive treatment.

Surgical care: Curettage, cryotherapy, and laser ablation may be used to treat small, superficial lesions. Surgical excision with a margin of normal tissue is generally recommended for all other lesions. This practice allows histological examination of the specimen for confirmation of the adequacy of excision. Surgery also provides a high cure rate. Excision of early tumors with a margin of normal tissue; the defect can be closed primarily or with skin grafts or local flaps. Advanced-stage tumors require a multidisciplinary approach, involving head and neck surgical oncologist, Mohs micrographic surgeons, pathologists, reconstructive plastic surgeons, prosthodontists, and anaplastologists. Neurosurgeons, ophthalmic surgeons, and radiotherapists may be included in selected patients.

Malignant melanoma

Primary cutaneous malignant melanoma is the leading fatal illness arising in the skin. As a result of a dramatic increase in incident and, to a lesser extent, an increase in death rate, this disorder, once considered rare, is now being widely studied. The American Cancer Society estimated that there would be 22,000 new cases of malignant melanoma 1985 in the United States, which surpasses the frequency of primary tumors of the brain, Hodgkin’s disease, carcinoma of the larynx or pharynx, and thyroid cancer. It has been suggested that cutaneous melanoma represents approxymately 2 percent of cancers by incidence (excluding nonmelanoma skin cancer) and 1 to 2 percent of cancer deaths.

Malignant melanoma, in contrast to many other forms of cancer, occurs chiefly during the reproductive years; there is a relatively flat incidence from age 20 to age 60 with the exception of lentigo maligna melanoma, one of the rarest types, that occurs predominantly in the elderly.

Melanoma is rare in early childhood; in this age group melanoma usually arises in association with congenital naevi. The tumor is a visible one. There are certain features, described in detail below, that should enable any-one, be it physician, medical student, nurse, to diagnose the disorder at an early and potentially surgically curable phase.

As a visible tumor, melanoma affords the opportunity to study the natural history and development of a malignancy that may eventually have a broader application to the understanding of cancer in general. Another aspect of increasing interest about melanoma is the intimate relationship that appears to exist between melanoma and the host’s immune system; the understanding and manipulation of this relationship may have tangible benefits for the management of this tumor.

Management of melanoma

Breslow and Macht have suggested that lesions less than 0.75 mm in thickness may be treated by surgical excision with smaller margins with favorable outcome. Recently, 1.5-cm margins for thin lesions have been suggested. A prospective study is presently under way by the World Health Organization in which 1-cm and 3-cm margins are being compared in a randomized trial for thin lesions.

Thicker lesions

For the more deeply invasive lesions, wide local excision with or without graft has been advocated as the primary therapy; and in many centers, if a defined drainage pathway can be determined, the draining lymph nodes are removed whether or not they are palpably enlarged. Previously, wide local excision meant 4- to 5-cm margins with grafting necessary for closure in nearly all cases. More recent recommendations propose a 3-cm margin with primary closure obtnainable in most instances. While the local recurrence rates may be increased somewhat with narrower margins, the overall survival rate does not appear to be diminished. Whether removal of lymph nodes containing microscopic foci of tumors ultimately benefits the patient is at present debatable. The Veronesi et al series from the World Health Organization has shown no increased survival with the elective removal when nodes become clinically palpable. Day et al showed an apparent benefit in patients with primary tumors less than 3.5 mm in thickness and less than four nodes involved with tumor.

Balch et al. showed a benefit in groups with tumors 1.5 to 3.99 mm thick. However, this question is far from settled and additional studies are necessary to determine the answer. Local excision also appears to be the most practical procedure for isolated local recurrences. Surgery has a very limited role to play, however, in the therapy of metastatic disease. Since isolated melanoma metastasis occasionally occurs, surgical excision of an isolated pulmonary nodule or a solitary lesion in an accessible area of the brain is sometimes performed with resultant long-term survival.