Skin Cancers and their treatment

BASAL CELL CARCINOMA (BCC, Rodent ulcer)

This is the commonest malignant tumour of the skin. It usually occurs in middle-aged or elderly fair-skinned individuals who have worked out of doors all their lives, or who have spent a lot of time gardening, fishing, sailing etc. Although due to sun damage, they do not occur at the sites of maximum sun exposure, i.e. rarely on the bald scalp, lowerip or dorsum of the hands. Most occur on the face, some on the trunk and limbs.  A basal cell carcinoma starts as a small translucent (pearly) papule which gradually increases in size, and the centre may then ulcerate and crust. Growth is very slow –some may reach a diameter of 1cm only after 5 years.

Treatment of Basal Cell Carcinoma

SQUAMOUS CELL CARCINOMA

Squamous cell carcinoma is less common on the skin than a basal cell carcinoma.  It arises from previously normal skin or from a pre-existing lesion such as a solar keratosis or Bowen’s disease.  Squamous cell carcinomas (SCCs) occur at sites of maximum sun exposure, i.e. on a bald head, the lower lip, cheeks, nose, top of ear lobes and dorsum of hands.  Well differentiated tumours produce keratin so the surface will be scaly or horny; later they may ulcerate and be covered with crust.   An SCC  grows quite fast (up to 1–2cm in diameter over a few months).

Treatment of Squamous Cell carcinoma

MALIGNANT MELANOMA

Two-thirds arise from normal skin and one-third from a pre-existing mole. There are four clinical patterns of malignant melanoma.

1. Lentigo maligna. A large (1–3cm size) brown patch on sun exposed skin in an elderly patient. The tumour cells are confined to the epidermis.  Later an invasive melanoma can develop with a lentigo maligna as a papule or nodule within the original patch.

2. Superficial spreading malignant melanoma. The initial growth phase of malignant melanocytes is along the dermoepidermal junction (radial growth phase). This change is seen clinically as a flat brown patch enlarging in diameter. Because the radial growth is usually uneven, there will be variation in the degree of pigmentation and an irregular border, often with scalloped edges. There may also be evidence of inflammation, erythema and sometimes an altered sensation.  Tumour cells remain high in the dermis and are unlikely to invade blood vessels or lymphatics. As a result superficial spreading melanomas generally carry a good prognosis. distinguished from the superficial spreading melanoma.

Nodular malignant melanoma

Here there is no radial growth and the malignant melanocytes grow down vertically from the start. The lesion is a nodule without any surrounding irregular pigmentation.  A typical nodular melanoma is a black dome shaped nodule. The surface of the lesion will eventually break down to bleed, ooze and crust over. Sometimes nodules may be red rather than brown.  The diagnosis can be delayed as there is no superficial spread to alert the patient, and prognosis is often poor as the lesion will be relatively thick before it has been diagnosed and removed.

Treatment of malignant melanoma

Surgical removal of the lesion is mandatory.  A margin of normal skin surrounding the melanoma is taken depending on how deep the melanoma has penetrated into the skin.  Often an initial diagnostic excision is performed, and a second wide excision carried out once the pathology has determined the type of lesion and its thickness.