Extramedullary plasmacytoma refers to the abnormal proliferation and localization of plasma cells outside the bone marrow, a condition that typically manifests as “extramedullary plasmacytoma” when plasma cells, normally found in the bone marrow, develop and proliferate in locations other than their usual site. Extramedullary plasmacytoma can occur when cancer cells spread or metastasize.

This phenomenon commonly appears in cancer diseases, particularly in hematologic cancers such as lymphoma and multiple myeloma. For instance, multiple myeloma is characterized by the abnormal proliferation and dissemination of plasma cells outside the bone marrow, which can occur in bones, lymph nodes, or other organs.

The diagnosis of extramedullary plasmacytoma is typically conducted using imaging tests (e.g., computed tomography or magnetic resonance imaging), bone marrow biopsy, and blood tests. Treatment approaches vary depending on the specific cancer type, the overall health of the patient, and the stage of the disease. Treatment options may include chemotherapy, radiotherapy, targeted therapies, and stem cell transplantation.