What type of cancer is characterized by the presence of abnormal plasma B cells?

The correct answer is myeloma, specifically referring to multiple myeloma. This type of cancer is indeed characterized by the proliferation of abnormal plasma B cells in the bone marrow. These plasma cells are responsible for producing antibodies, and when they become cancerous, they lead to various clinical manifestations including bone pain, anemia, and increased risk of infections due to compromised immune function.

Multiple myeloma specifically affects the bone marrow, leading to an overproduction of monclonal immunoglobulins which can interfere with normal plasma cell function and disrupt the production of other blood cells. The presence of these abnormal plasma cells can be identified through diagnostic tests, including serum protein electrophoresis, that detect the excess presence of a specific immunoglobulin.

In contrast, leukemia is a cancer of the blood and bone marrow that involves the rapid proliferation of abnormal white blood cells, while lymphoma primarily affects the lymphatic system and can involve lymphocytes but is not specifically characterized by abnormal plasma B cells. Carcinoma denotes cancer that originates in epithelial tissues, which is distinct from the hematologic cancers mentioned. Therefore, myeloma is the precise term that describes the condition related to abnormal plasma B cells.