Other malignancies

Dermatofibrosarcoma protuberans (Fig. 13.45)

This is a locally malignant tumour arising in the dermis and composed of more or less mature fibroblasts. It is usually situated on the trunk, particularly in the flexural regions, and in its early stages can look very similar to a histiocytoma. Treatment is by wide excision with a margin of 3 cm. Local recurrence invariably follows inadequate surgery.

Kaposi’s sarcoma

This is a neoplasm of multifocal origin derived from proliferating capillary vessels and perivascular connective tissue cells. In Europeans, it is a disease of late adult life, running an indolent course affecting the legs of elderly men. Amongst the immunocompromised population it appears much earlier. There is an endemic form in various parts of Africa. The tumour also occurs in association with acquired immuno deficiency syndrome (AIDS). The AIDS-related form runs a rapid course with painful lesions at multiple sites and metastatic spread. The lesions have a dark blue or purplish colour. At first they are macular, and when they become tumid, pressure may produce blanching to reveal a brown tinge. The process usually begins on the extremities, most commonly on the feet, but occasionally on the hands, ears or nose. Treatment is by radiotherapy.

Angiosarcoma

This is a rare tumour largely seen in elderly males. The lesions occur most commonly on the scalp or face and may present either as a subcutaneous plaque in the skin, as a nodule, particularly on the scalp, or as a single or multiple bluish-purple discoloration of the skin. Metastatic disease is largely to the cervical lymph nodes and lungs.

Lymphangiosarcoma

This is a long-standing complication of lymphoedema and it occurs on the brawny oedematous arm of the postradical mastectomy patient or in a lower limb following groin dissection. Conservative breast surgery and the use of special elastic compression stockings have made this condition much less common. It is usually fatal.

Primary cutaneous malignant lymphoma

This is rare and can be divided broadly into three types:

  mycosis fungoides and Sezary syndrome (a rare and fatal reticulosis with unusual giant cells in the blood and skin);

  primary cutaneous non-Hodgkin’s lymphoma;

  primary cutaneous Hodgkin’s lymphoma.

Mycosis fungoides is a term given to a condition characterised by initial infiltration of the skin by malignant lympho­cytes with subsequent involvement of lymph nodes, spleen, liver, bone marrow and other organs. Patients usually present between the ages of 40 and 60 years with a long-standing history of dermatitis, exfoliative erythroderma or a papular rash, which in time progresses to plaque and then tumour formation. The diagnosis of lymphoma of the skin should be made by a biopsy and treatment is by radiotherapy and/or chemotherapy.

Merkel cell tumour

Merkel cell tumour (trabecular cell carcinoma, primary neuroendocrine carcinoma) arises from Merkel cells as an enlarging blue—red nodule (Fig. 13.46). Local metastases occur in 75 per cent and distant spread in 25 per cent of cases. Treatment is by surgical excision of the primary with a 2—5-cm margin followed by radiotherapy to the site of the primary and the regional nodal basin.

Metastatic malignant tumours

These are tumours formed by malignant cells originating from another site, and frequently from another tissue, con­veyed to the skin by the blood and lymphatic circulation. The skin is not uncommonly secondarily involved by malignant lymphoma and leukaemia as a manifestation of generalised disease. Most malignant tumours can produce cutaneous metastases, but some seed to the skin more than others. Hypernephroma, an uncommon malignancy, accounts for 9 pen cent of skin metastases. The most frequent primary sites are breast, stomach, lung, uterus, large intestine, kidney, prostate gland, ovary, liver and bone.