Plasmacytoma: Any discrete, presumably solitary, mass of neoplastic PLASMA CELLS either in BONE MARROW or various extramedullary sites.Skull Neoplasms: Neoplasms of the bony part of the skull.Multiple Myeloma: A malignancy of mature PLASMA CELLS engaging in monoclonal immunoglobulin production. It is characterized by hyperglobulinemia, excess Bence-Jones proteins (free monoclonal IMMUNOGLOBULIN LIGHT CHAINS) in the urine, skeletal destruction, bone pain, and fractures. Other features include ANEMIA; HYPERCALCEMIA; and RENAL INSUFFICIENCY.Myeloma Proteins: Abnormal immunoglobulins characteristic of MULTIPLE MYELOMA.Neoplasms, Plasma Cell: Neoplasms associated with a proliferation of a single clone of PLASMA CELLS and characterized by the secretion of PARAPROTEINS.Paraproteins: Abnormal immunoglobulins synthesized by atypical cells of the MONONUCLEAR PHAGOCYTE SYSTEM. Paraproteins containing only light chains lead to Bence Jones paraproteinemia, while the presence of only atypical heavy chains leads to heavy chain disease. Most of the paraproteins show themselves as an M-component (monoclonal gammopathy) in electrophoresis. Diclonal and polyclonal paraproteins are much less frequently encountered.Immunoglobulin Heavy Chains: The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.Mice, Inbred BALB CNeoplasms, Experimental: Experimentally induced new abnormal growth of TISSUES in animals to provide models for studying human neoplasms.Immunoglobulin kappa-Chains: One of the types of light chains of the immunoglobulins with a molecular weight of approximately 22 kDa.Monoclonal Gammopathy of Undetermined Significance: Conditions characterized by the presence of M protein (Monoclonal protein) in serum or urine without clinical manifestations of plasma cell dyscrasia.Immunoglobulin lambda-Chains: One of the types of light chain subunits of the immunoglobulins with a molecular weight of approximately 22 kDa.Mineral Oil: A mixture of liquid hydrocarbons obtained from petroleum. It is used as laxative, lubricant, ointment base, and emollient.Paraproteinemias: A group of related diseases characterized by an unbalanced or disproportionate proliferation of immunoglobulin-producing cells, usually from a single clone. These cells frequently secrete a structurally homogeneous immunoglobulin (M-component) and/or an abnormal immunoglobulin.Maxillary Sinus Neoplasms: Tumors or cancer of the MAXILLARY SINUS. They represent the majority of paranasal neoplasms.Bone Neoplasms: Tumors or cancer located in bone tissue or specific BONES.POEMS Syndrome: A multisystemic disorder characterized by a sensorimotor polyneuropathy (POLYNEUROPATHIES), organomegaly, endocrinopathy, monoclonal gammopathy, and pigmentary skin changes. Other clinical features which may be present include EDEMA; CACHEXIA; microangiopathic glomerulopathy; pulmonary hypertension (HYPERTENSION, PULMONARY); cutaneous necrosis; THROMBOCYTOSIS; and POLYCYTHEMIA. This disorder is frequently associated with osteosclerotic myeloma. (From Adams et al., Principles of Neurology, 6th ed, p1335; Rev Med Interne 1997;18(7):553-62)Respiratory Tract NeoplasmsImmunoglobulin delta-Chains: The class of heavy chains found in IMMUNOGLOBULIN D. They have a molecular weight of approximately 64 kDa and they contain about 500 amino acid residues arranged in four domains and an oligosaccharide component covalently bound to the Fc fragment constant region.Genes, Immunoglobulin Light Chain: Genes and gene segments encoding the IMMUNOGLOBULIN LIGHT CHAINS. Gene segments of the light chain genes are designated as V (variable), J (joining), and C (constant).Immunoglobulin Light Chains: Polypeptide chains, consisting of 211 to 217 amino acid residues and having a molecular weight of approximately 22 kDa. There are two major types of light chains, kappa and lambda. Two Ig light chains and two Ig heavy chains (IMMUNOGLOBULIN HEAVY CHAINS) make one immunoglobulin molecule.Immunoglobulin mu-Chains: The class of heavy chains found in IMMUNOGLOBULIN M. They have a molecular weight of approximately 72 kDa and they contain about 57 amino acid residues arranged in five domains and have more oligosaccharide branches and a higher carbohydrate content than the heavy chains of IMMUNOGLOBULIN G.Terpenes: A class of compounds composed of repeating 5-carbon units of HEMITERPENES.Immunoglobulin alpha-Chains: The class of heavy chains found in IMMUNOGLOBULIN A. They have a molecular weight of approximately 58 kDa and contain about 470 amino acid residues arranged in four domains and an oligosaccharide component bound covalently to their Fc fragment constant region.Ilium: The largest of three bones that make up each half of the pelvic girdle.Translocation, Genetic: A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.