A 56-year-old woman with a history of breast cancer that was treated 5 years ago with lumpectomy and radiation but with no chemotherapy returns with bone pain, fatigue, and weakness. A complete blood count reveals severe anemia, as well as decreased white blood cells and platelets. Examination of a peripheral blood smear reveals small numbers of nucleated red cells, as well as an occasional "blast" cell and myelocyte. A likely cause of the hematologic abnormalities is
High-Yield Explanation
- Infiltration of tumor cells from cancers, those of breast & prostate - displaces bone marrow elements, thereby causing myelophthisic anemia. OTHER OPTIONS: - Chloramphenicol causes aplastic anemia in some individuals. - Diphyllobothrium latum infestation can result in megaloblastic anemia due to vitamin B12 deficiency.