Anaplastic Atypical Myeloma with Extensive Cutaneous Involvement in a Dog

Abstract

ABSTRACT. A 7-year-old, male, mixed breed dog was referred to the Veterinary Teaching Hospital at Kitasato University because of anorexia, lameness and multiple cutaneous lesions. Observation of bone marrow plasmacytosis, osteolytic bone lesions, serum myeloma protein and cutaneous infiltration of myeloma cells led us to a diagnosis of multiple myeloma (MM) with cutaneous involvement. Polymerase chain reaction and sequence analysis for the rearranged genes of immunoglobulin and T-cell receptor demonstrated that the neoplastic cells found in skin lesions or bone marrow are of B-lymphocyte lineage and share a common original precursor cell. The dog was treated with UW-Madison protocol or melphalan/prednisone protocol and survived 175 days. This is rare case of anaplastic MM with cutaneous involvement in dog.

What is your diagnosis? Cutaneous nodules and atypical blood cells in a dog

“…Since a monoclonal gammopathy was not present, this MM was nonsecretory; a rare occurrence in dogs and humans for which it accounts for less than 1% of MM cases . As in this case, the few reports in veterinary medicine presented single or multiple osteolytic lesions and increased plasma cell numbers in bone marrow aspirates or biopsies (more than 20%; normal 5%) …”

“…1 As in this case, the few reports in veterinary medicine 3,4 presented single or multiple osteolytic lesions and increased plasma cell numbers in bone marrow aspirates 3 or biopsies 4 (more than 20%; normal 5%). 1,2 The clinical signs of MM are variable, but often include lameness and polyuria/polydipsia, as presented here. However, cutaneous metastases are rare-to date, only 3 cases have been reported with 40-50 nodules on the abdominal and inguinal regions in 2 older dogs, 2,5 and over 180 masses covering the neck, trunk, and limbs in a young animal.…”

“…Multiple myeloma is a rare neoplasia, accounting for 0.3% of all malignant tumors and 2% of canine hematopoietic neoplasms. It typically affects older animals, between 8 and 12 years old, and its diagnosis relies on the presence of at least 2 of the following: (1) light chain proteinuria; (2) monoclonal gammopathy in serum electrophoresis; (3) bone marrow plasmacytosis; and (4) osteolysis . The latter 2 criteria were present herein.…”

“…The clinical signs of MM are variable, but often include lameness and polyuria/polydipsia, as presented here. However, cutaneous metastases are rare—to date, only 3 cases have been reported with 40‐50 nodules on the abdominal and inguinal regions in 2 older dogs, and over 180 masses covering the neck, trunk, and limbs in a young animal . In people, cutaneous metastases are also rare and due, presumably, to changes in adhesion molecules, such as syndecan‐1; in dogs, the mechanism is unknown.…”

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

“…MMs account approximately 2% of all hematopoietic neoplasms in both dogs and cats [4]. Most of the reports in the literature are limited to 1 to 16 case studies [4,[11][12][13][14][15][16]. However, in a recent report regarding the incidence of bone disorders diagnosed in dogs, MM was the second most frequently diagnosed neoplastic condition in canine bone marrow [17].…”