A human breast stromal sarcoma cell line with features of malignant cystosarcoma phyllodes.

A cell line was established from a portion of a 25-cm stromal sarcoma of the left breast of a 65-year-old woman. The clinical course was rapid with tumor recurrence on the chest wall less than 1 month after mastectomy. Other cutaneous and abdominal metastases occurred shortly thereafter, and death followed within 3 months despite chemotherapy. The cultured cells, designated RW-972, produced large amounts of acid mucopolysaccharides (hyaluronic acid) and mimicked the aggressive growth characteristics seen in the patient. After injection into nude mice, the tumor grew rapidly and occasionally produced metastases. This unique cell line, RW-972, presumably derived from the stromal component of a human malignant cystosarcoma phyllodes, might be useful in studies of experimental therapy of this rare tumor type and of lobular stromal cells of breast. It may also be used to investigate hyaluronic acid production by tumor cells.