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
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