Skin Signs of Internal Cancers II

​​This skin disease presents as corn-like hardening of the skin resulting from chronic ingestion of arsenic. Arsenic may be found in some herbal medication which was especially used for the treatment of asthma previously. The skin lesions first develop on the palms and soles and subsequently the trunk and limbs.

With the passage of time, each individual lesion may become cancerous. The skin disorder may be associated with cancers of the lung, throat and genito-urinary region.

Paget's disease of the nipple presents as a red, crusted patch around the nipple. This skin disease which may be mistaken for eczema is often associated with breast cancer.

Patients with this condition are red and scaly over practically their entire body surface. There may be swelling of the skin, fever and debilitation. About 10 to 15% of such patients have an internal cancer, the commonest of which is a lymphoma (a cancer of cells of the lymph glands).

​​This condition is characterised by brown or black spots on the lips and inside the mouth. It is inherited in an autosomal dominant manner, but up to 50% of patients do not have any familial predisposition for the condition.

A small percentage of these patients have associated cancer of the gut, breasts or ovaries.

​​This condition is an inherited disorder. It is marked by multiple benign tumours (neurofibromas) on the skin. 2 to 5% of the patients develop an internal cancer.

These patients may develop tumours in the brain (astrocytoma, glioblastomas) and adrenal glands (phaeochromocytomas). Patients with neurofibromatosis who develop headache, backache or hypertension should be investigated for internal cancers.

Any internal cancer can spread to the skin. Skin lesions due to the spread of internal cancers are called "metastases". The tumours that most frequently give rise to skin metastases in Singapore include lung cancer, colorectal cancer and breast cancer. The presence of metastases in the skin usually means that the internal cancer has spread to other organs as well.

Site
Certain sites appeared to be favoured by particular tumours although generalisations are not possible. For example, the scalp, face and neck are the commonest sites of metastases from breast, lung and oral cavity cancers. Metastases on the chest is most often from breast or lung cancer. The name "Sister Joseph's nodule" has been given to metastases on the navel from cancer in the abdomen, pelvis or breast.

Clinical Features
Metastases in the skin may appear as single or multiple nodules. The nodules are usually firm or hard, fixed or mobile and non-tender. They often grow rapidly to 1 to 3 cm in diameter. The colour is variable and may be red, brown, blue, black or flesh coloured.

Management
When cutaneous metastasis is suspected, a specimen of the lesion should be surgically removed (skin biopsy) to confirm the diagnosis. If cancerous metastasis is confirmed the patient should undergo investigation to determine the site of the internal cancers.

​Treatment of the patient depends on the type of primary tumour, the degree of spread and the overall physical condition of the patient. Medical options for therapy include radiotherapy and chemotherapy.