plasma cell neoplasm (Monarch Disease Ontology identifier MONDO_0004959) is a clonal proliferation of immunoglobulin-secreting plasma cells. This category includes plasma cell myeloma, plasma cell leukemia, plasmacytoma, monoclonal immunoglobulin deposition disease, and monoclonal gammopathy of undetermined significance. Also known as: plasma cell dyscrasia, plasma cell tumor, plasma cell tumor, malignant, plasma cell tumour, plasmacytic neoplasm, plasmacytic tumor, plasmacytic tumour.