Sarcomatous dermatofibrosarcoma protuberans metastasized to the lung: Preservation of CD34 expression in tumor cells

A case of metastatic dermatofibrosarcoma protuberans (DFSP) in a 47-year-ol d woman is presented. Dermatofibrosarcoma protuberans occasionally recurs, but rarely metastasizes. The patient underwent local removal of the nuchal tumor by a general practitioner, followed by a rapid recurrence. She underw ent total removal of the tumor and a diagnosis of spindle cell sarcoma was made after an incisional biopsy was performed. This lesion had both a typic al DFSP-like area and a fibrosarcoma (FS)-like area. After 7 years, an abno rmal lung shadow was observed and a segmental lung resection was performed. Histologically, the lung tumor was similar to the FS-like area in the nuch al tumor. Confirming CD34 expression in the tumor cells, this lung tumor wa s diagnosed as metastatic DFSP. Usually CD34 expression is unique to DFSP b ut almost negative in FS-like areas. In the present case, the FS-like area in the nuchal tumor showed decreased CD34 reactivity, as previously reporte d, but the FS-like area in the metastatic tumor still widely preserved CD34 expression. The presented case suggests that the FS-like area in DFSP is h istogenetically different from typical FS or malignant fibrous histiocytoma .