[Metastatic Darier-Ferrand dermatofibrosarcoma. Review of the literature apropos of a case]

We report the case of a 56-year old male patient with pulmonary, abdominal and pelvic metastases from a dermatofibrosarcoma (DFS) which had developed 23 years previously in the right scapulo-humeral region and had recurred twice after the first excision, in 1983. Surgery was only performed once. The most remarkable feature of the disease was the progressive transformation, with each recurrence, of a typical DFS into a poorly differentiated and highly malignant tumour, about as active as a fibrosarcoma. A review of the literature yielded 31 cases of histologically proven metastatic DFS. Although the actual incidence of metastases is difficult to determine with accuracy, their frequency may be estimated at 3 p. 100 (most probably a maximum figure). The disease spreads mostly through the blood, but also sometimes through the blood and lymph. However, since lymphatic involvement is rare the usefulness of lymph node excision is extremely doubtful. Pulmonary lesions are the most frequent ones, but various other organs may be affected, although this seldom applies to the liver. Following a first excision, metastases occur within 6 years on average (range: 1 to 33 years). This mean delay is superior to the mean follow-up period for most of the important series without metastases. The histopathological picture is usually one of typical DFS but in some cases, including ours, it is much less typical and may even be frankly malignant. A few reports mention the presence of histiocytic infiltrates associated with the fibroblasts. The prognosis in patients with metastases is particularly poor: in most of the cases reported the patient died within the year following the discovery of metastatic lesions. The very high progressivity of the secondary lesions contrasts with the slow course of the primary tumour. None of the treatments tried (surgery, radiotherapy, chemotherapy) has resulted in a significant prolongation of life. No correlation can be established between the occurrence of metastases and the following parameters taken together: patient's age and sex, tim elapsed between the appearance of the tumour and the date of exicision, and histological features of the initial tumour. The development and number of recurrences seems to be the most significant predictive factor as regards the risk of metastasis. The noxious role of incomplete and/or repeated surgery creating vascular breaks, disrupting the defense barriers and encouraging malignancy in some cases has been mentioned by most authors; it emphasizes the value of the widest possible initial surgery.(ABSTRACT TRUNCATED AT 400 WORDS)