Dermatofibrosarcoma protuberans. A histological and ultrastructural study of 11 cases with emphasis on the study of recurrences and histogenesis.
Eleven cases of dermatofibrosarcoma protuberans (DFSP) (6 male: 5 female; mean age +/- SD: 48.7 +/- 16.1 years) were reviewed in an attempt to correlate the histological and ultrastructural findings with the recurrence pattern of these tumours and to shed light on their histogenesis. Six (54.5%) of the tumours recurred: 3 with a similar appearance to the primary tumours, 2 with fibroblastic malignant fibrohistiocytic pattern (F-MFH), and one with fibrosarcomatous features (F), confirmed ultrastructurally. In one primary tumour with associated F features there were two recurrences. The ultrastructural findings of 6 primary tumours (2 with and 4 without recurrences) showed a predominance of primitive mesenchymal cells. The comparison between the features (sex, age, site, necrosis, mitotic rate size) of recurring DFSP vs DFSP without recurrences did not yield any significant difference. At follow-up (range: 11-108 months) all patients were alive and well. These findings support the assumption that DFSP originates from primitive mesenchymal cells that are able to show, at least, F and F-MFH differentiation, and corroborate the low-grade malignancy of DFSP regardless of their macroscopic, histologic and ultrastructural characteristics.
Lopes
J M
JM
Department of Pathology of Porto Medical School, Hospital de S. João, Portugal.
Paiva
M E
ME
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005354:Fibrosarcoma / Q000209:etiology / Q000473:pathology*; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D013997:Time Factors