Fine-needle aspiration cytology of metastatic breast tumor originating from leukemia.

Two cases of metastatic breast tumor originating from leukemia are reported. Fine-needle aspiration (FNA) specimens showed a large number of isolated small-to-medium-sized atypical lymphocytic cells. It is difficult to distinguish metastatic breast tumors and primary breast cancers by physical findings alone. FNA cytology is an effective method for qualitative diagnosis. When atypical lymphocytic cells are obtained in aspiration materials of the breast, past history and general examination are necessary for diagnosis. In some cases of leukemia with breast involvement, good outcomes are obtained. Therefore, earlier detection is necessary in order to begin suitable therapy earlier and to avoid unnecessary excisional biopsy in patients with leukemia and breast tumors. To achieve this it is also necessary to first take into consideration the possibility of metastasis or infiltration of leukemia, and second to prepare two types of specimen for Papanicolaou stain and Giemsa stain before operation.