Unusual IgM-secreting multiple myeloma in a dog

Abstract

A 4-year-old castrated male dog was evaluated because of multiple-limb lameness. Signs of pain were elicited during palpation of the regions of the proximal tibial metaphyses and distal left radial diaphysis. Radiography revealed osteolytic lesions of the long bones. Blood analyses revealed hypercalcemia and transient cytopenias. Serum protein electrophoresis did not reveal a monoclonal gammopathy; however, urine protein electrophoresis revealed Bence Jones proteinuria. Serial diagnostic sampling of bone lesions, immunohistochemical staining methods, and serum and urine protein immunoelectrophoresis were required to establish a diagnosis of multiple myeloma. Two IgM components were identified via serum protein immunoelectrofixation. The dog improved clinically after initiation of chemotherapy with melphalan and prednisone; however, the dog ultimately was euthanatized because of pathologic fracture. The case was unique because there was lack of vertebral involvement, an unusual gammopathy, and difficulty in identifying myeloma cells via serial sampling.

Paraplegia in a Bornean orangutan (Pongo pygmaeus pygmaeus) due to multiple myeloma

“…Similar to tumors in humans, those in cats and especially dogs have a predilection for the axial skeleton resulting in spinal pain and neurological deficits, very similar to the orangutan described in this study. Therefore, a common history in affected animals is presentation with changes in gait, hind limb lameness, ataxia or paresis, and pain along the vertebral column [5].…”

“…No amyloidosis was observed in the orangutan described in this study. In animals, there is only one report of plasmacytoma‐associated systemic amyloidosis in a horse and very few observations on cutaneous amyloid deposition due to monoclonal gammopathies in dogs and horses [2, 5, 15].…”

“…In humans, this rare tumor accounts for about 1–2% of malignancies, occurring slightly more often in older males than females. In domestic animals, dogs are mostly affected, followed by cats and horses, while multiple myeloma represents a rather rare disease in farm animals including cattle and pigs [1–7]. A single case of non‐medullary plasma cell tumor has been reported in a rhesus monkey in which neoplastic cells infiltrated mainly the renal interstitium, lymph nodes, and spleen with only very few tumor cells in the bone marrow, not classifying for medullary plasmacytoma [8].…”

Multiple Myeloma in Horses, Dogs and Cats: A Comparative Review Focused on Clinical Signs and Pathogenesis

“…MM is generally a disease of older animals, although some reports exist in young animals. In dogs, the average age of diagnosis is between 8 and 12 year-old [9][10]15,[19][20][21][22][23][24][25].There is a report of MM in a younger dog, 4-year-old [26]. There is no apparent gender predisposition…”

“…Anemia is a prominent feature of MM, it is commonly associated with clinical progression in human patients and occurs in more than two thirds of all patients [130][131][132]. Similarly, approximately 30% of dogs and 75% of cats with MM have a normocytic normochromic non-regenerative anemia [4,10,[26][27][32][33] and anemia is also invariably present in horses with MM.…”