Diagnosing Multiple Myeloma and Related Disorders.

This review provides current information on myeloma-related disorders, a group of plasma cell or immunoglobulin (Ig) secreting neoplasms including multiple myeloma, extramedullary plasmacytoma (both cutaneous and noncutaneous variants), solitary osseous plasmacytoma, Waldenström macroglobulinemia/lymphoplasmacytic lymphoma, Ig-secretory B-cell lymphoma, plasma cell leukemia, and monoclonal gammopathy of undetermined significance. The diagnostic procedures commonly used to characterize myeloma-related disorders, including cytopathology, histopathology, polymerase chain reaction for antigen receptor rearrangement, flow cytometry, and electrophoretic techniques are outlined and discussed.

Lymphoplasmacytoid lymphoma in a cow.

Lymphoplasmacytoid lymphoma was found in an 8-year-old Holstein cow uninfected with bovine leukemia virus (BLV). The neoplastic tissue was composed of lymphoid and plasmacytoid cells, and intracytoplasmic IgM (lambda) was detected in the latter. The diagnosis was based on the presence of small lymphoid cells and the expression of CD5, which were suggestive of a close relationship with chronic lymphocytic leukemia. Areas of immunoblastoid cells were reminiscent of histologic progression into immunoblastic lymphoma. The neoplastic cells at different stages of differentiation were distinct from those of BLV-associated pleomorphic lymphoma.

Monoclonal cryoglobulinemia with macroglobulinemia in a dog.

A 9-year old female Doberman Pinscher had a 5-month history of epistaxis. On routine testing of the dog's serum, blockage of the intake tubes of the equipment resulted. At this point, cryoglobulinemia was suspected and was later confirmed to be due to a monoclonal cryoglobulin (IgM), by means of immunochemical studies. Clinical recovery was achieved by use of cytotoxic drugs.

Hyperviscosity syndrome associated with lymphocytic leukemia in three dogs.

Hyperviscosity syndrome was associated with increased plasma content of monoclonal immunoglobulin (IgA or IgM) in 3 dogs with lymphocytic leukemia. The diagnosis of lymphocytic leukemia was based on the finding of a large number of mature lymphocytes in the blood and bone marrow. The clinical signs included weakness, lethargy, depression, and coughing due to congestive heart failure. Consistent physical findings were splenomegaly, with or without peripheral lymphadenopathy, and funduscopic abnormalities. Of the 2 dogs treated successfully with chlorambucil, 1 remains in remission after withdrawal of the drug for over 1 year.

Immunoglobulin-producing tumors.

Multiple myeloma and macroglobulinemia are the most common immunoglobulin-producing neoplasms seen in the dog. Treatment with the alkylating agents in combination with prednisone may significantly prolong survival. Supportive management of associated complications is imperative to ensure that the individual case receives optimal care. The use of clinical staging seems to be of value in establishing prognosis; however, response to therapy may be more significant, for many dogs present with advanced disease. In the high-risk patient, one should consider using investigational combination drug protocols which are available at a referral center. Although a "cure" is unlikely, the prospect of the animal having a fairly normal, healthy life for an extended period of time (over a year in the majority of cases) should encourage veterinarians to recommend evaluation for treatment in dogs with multiple myeloma and macroglobulinemia.

Case report: Macroglobulinemia in a dog.

This report describes a case of macroglobulinemia in a six year old castrate male Collie cross dog with clinical signs of epistaxis, anemia, retinopathy and high serum viscosity. The highest total serum protein was 12 g/dl with approximately 60% monoclonal beta globulin. Proteinuria, Bence Jones protein and osteolytic lesions were not detected.Chemotherapy and partial removal of the plasma protein by withdrawal of whole blood and transfusion with packed red cells from a DEA negative donor resulted in transient clinical remission.

Waldenström's macroglobulinemia in a dog with a bleeding diathesis.

An 11-year-old female spayed Whippet dog was referred to the Veterinary Hospital of the National Veterinary School of Lyon with a 3-month history of chronic bleeding, cutaneous masses suggestive of hematomas, and hemorrhagic diarrhea. Laboratory abnormalities included leukopenia with neutropenia and lymphopenia, rouleaux formation, marked hyperproteinemia with hyperglobulinemia and normoalbuminemia, hypercalcemia, markedly increased serum urea concentration, mildly increased creatinine concentration, and proteinuria. Hemostatic screening tests showed marked prolongation of thrombin time, increased concentrations of fibrin(ogen) degradation products and D-dimers, and slightly prolonged activated partial thromboplastin time. Serum and urine protein electrophoresis revealed a monoclonal peak identified as IgM by immunoelectrophoresis and an M-spike, respectively. Cytologic evaluation of bone marrow revealed a hypocellular sample with lymphoplasmacytic cells comprising approximately 50% of all nucleated cells. These findings were consistent with a diagnosis of Waldenström's macroglobulinemia with secondary bleeding diathesis. Treatment with prednisone and chlorambucil was initiated, and the dog had a good response.