Canine Indolent Nodular Lymphoma

Abstract

Abstract. Sixty-six cases of indolent canine lymphoid proliferation were reviewed. Age ranged from 1.5 to 16 years (median 9.0 years). Dogs of 26 breeds, plus 13 of mixed breeding or unknown lineage, were represented. B-Cell lymphomas (CD79a + ) predominated. Marginal zone lymphoma (MZL), the largest group, involved lymph node (33 cases) and spleen (13 cases), with both tissues involved in five of these cases. Follicular lymphoma (FL) involved lymph nodes (five cases), and mantle cell lymphoma (MCL) occurred as solitary splenic masses (three cases). Nodal CD3 + T-zone lymphomas (TZL) (10 cases), were included since they resembled late-stage MZL at the architectural level. Two cases of marginal zone hyperplasia (MZH) were included to aid in differentiation of early MZL. Clonality status was determined in 54 cases by analysis of immunoglobulin heavy chain (IGH) and T-cell antigen receptor gamma (TCRG) gene rearrangement. Clonal rearrangement of IGH was detected in 28 of 35 MZL cases (80%), four of four FL cases (100%) and three of three MCL cases (100%). Concurrent cross lineage rearrangement of TCRG was detected in six MZL and two FL cases. Clonal rearrangement of TCRG was documented in five of eight TZL cases (63%). Limited survival data obtained for 18 dogs indicated that the B-cell lymphomas (MZL, MCL, and FL) and the T-cell lymphoma (TZL) were associated with indolent behavior and long survival. Although to the authors' knowledge, the true incidence of canine indolent lymphomas is unknown, the tumors are not rare and may have been underrecognized. Recognition of their architectural features, routine application of immunophenotyping, and molecular clonality assessment should alleviate this.

Immunophenotyping and Gene Rearrangement Analysis in Dogs with Lymphoproliferative Disorders Characterized by Small-Cell Lymphocytosis

“…4 More recently, a similar assay was developed based on the canine genome database by targeting the T-cell receptor gamma chain (TCRc) gene 15 and the immunoglobulin heavy chain (IgH) gene. 9 Although the diagnostic value of PCR analysis has been demonstrated in several types of lymphoproliferative disorders, 7,[11][12][13][14] only limited studies have been done to identify neoplastic proliferation of lymphocytes in dogs with small-cell lymphocytosis. In the present study, immunophenotypical evaluation was performed on the blood of dogs with small lymphocytosis.…”

Flow Cytometric Characterization and Clinical Outcome of CD4+ T‐Cell Lymphoma in Dogs: 67 Cases

“…Further subclassification within the T‐cell phenotype has identified important subtypes that are associated with both aggressive disease (pleomorphic mixed/peripheral T cell, plasmacytoid, T‐cell lymphoblastic) and indolent disease (small clear cell/T zone lymphoma) 1, 2. This distinction, important for both prognosis and rational selection of chemotherapy protocol, is currently made by histologic examination of tissue specimens.…”

Application of Polymerase Chain Reaction to Analysis of Antigen Receptor Rearrangements to Support Endoscopic Diagnosis of Canine Alimentary Lymphoma

“…The polymerase chain reaction (PCR) for antigen receptor gene rearrangement analysis (PARR) was developed for diagnosis of lymphoid neoplasia [3,17]. Lymphocytes have acquired a unique antigen receptor gene of a unique length and sequence by gene rearrangement.…”

“…In PARR, clonal expansion of tumor lymphocytes that contain a rearranged immunoglobulin heavy chain (IgH) gene or a T cell receptor gamma (TCR) gene can be detected in B-cell and T-cell lymphoid neoplasias, respectively. PARR is an objective and highly sensitive method, and its usefulness in diagnosis of canine lymphoid neoplasia has recently been proven [3,8,10,17]. In the present study, we evaluated the usefulness of PARR using endoscopic biopsy specimens in diagnosis of alimentary lymphoma.…”