Metastatic cystosarcoma phyllodes. A report of 2 cases presenting with neurological symptoms.

Two cases of cystosarcoma phyllodes of the breast are presented with central nervous system (CNS) metastases appearing several years after mastectomy for the primary lesion. Unusual features in these cases include the widespread metastases themselves, neurologic symptomatology and CNS involvement, metastases into a uterine leiomyoma and into an area of hepatic adenomatous hyperplasia, and glomus-like structures in one of the primaries with similar structures resembling glomus cells in metastases. The distant metastases were of stromal cells only and frequently surrounded epithelial cells to isolate the indigenous glandular structures. The concept that cytosarcoma is a peculiar stromal neoplasm rather than a tumor of dual neoplastic origin is discussed.