Page 714 - Withrow and MacEwen's Small Animal Clinical Oncology, 6th Edition

692 PART IV Specific Malignancies in the Small Animal Patient

TABLE 33.1 World Health Organization Classification System for Canine Lymphoma
PERCENTAGE
VetBooks.ir Category Seelig et al 96 Vezzali et al 98 University of Wisconsin

(n = 3 data sets)
(n = 122)
(n = 123)
B-Cell Neoplasms 69 78.9 59.0
Precursor B lymphoblastic leukemia/lymphoma a — 2.4 8.2
B-cell chronic lymphocytic leukemia/small lymphocytic lym- — 2.4 0.8
phoma
Lymphocytic lymphoma—intermediate type — 0.8 —
Lymphoplasmacytic lymphoma — 3.3 0.8
Mantle cell lymphoma 2 1.6 —
Follicular center cell lymphomas — 2.4 —
Marginal zone lymphoma (splenic, nodal, mucosa-associated 8 3.3 2.5
lymphoid tissue)
Plasma cell myeloma/plasmacytoma — 16.3 9.8
Diffuse large cell lymphoma 52 33.3 24.6
T-cell–rich, B-cell lymphoma — 0.8 —
Large cell immunoblastic lymphoma — 10.6 10.7
Mediastinal (thymic) large B-cell lymphoma — 0.8 —
Burkitt’s lymphoma/leukemia — 0.8 1.6
Other B cell 8 d — —
T-Cell and Natural Killer (NK ) Cell Lymphomas 31 21.1 41.0
b
Precursor T lymphoblastic lymphoma/leukemia a 3 6.5 9.8
T-cell chronic lymphocytic leukemia (CLL) — 3.3 0.8
Intestinal T-cell lymphoma — 4.1 4.1
Mycosis fungoides/Sézary syndrome — 1.6 11.5
Cutaneous nonepitheliotropic lymphoma — 3.3 —
Anaplastic large cell lymphoma — — 0.8
Peripheral T-cell lymphoma-not otherwise specified 15 2.4 13.1 c
T-zone lymphoma 4
Other T cell 7 d — —
Other 3 d
a Acute leukemias and lymphoblastic lymphomas of both B and T derivation are also classified as lymphoid “precursor neoplasms.”
b Non-B, non-T lymphomas.
c Includes T-zone lymphoma in this data set.
d Other in Seelig include those not otherwise subclassified.

prognosis. Preliminary results indicate that dogs with indolent investigators to “translate” among the numerous classification sys-
lymphoma (e.g., MZL, follicular lymphoma, B- or T-cell small tems so that clinical trials could be compared in humans. Most
cell lymphoma, T-cell–rich B-cell lymphoma, and TZL) maintain of the larger compilations agree that most canine lymphomas are
normal activity and appetite levels even during advanced stages of intermediate or high grade. The WF categorizes tumors according
disease and experience long-term survival even with limited or no to pattern (diffuse or follicular) and cell type (e.g., small cleaved
therapy. 90,99–102 cell, large cell, immunoblastic), but it does not include informa-
Other classification systems that have been used include the tion about the immunophenotype of the tumor. 103 The WF sub-
National Cancer Institute Working Formulation (WF) 103 and types are related to the biology of the tumor and patient survival.
the updated Kiel system. 104 The WF was developed to allow The updated Kiel classification includes the architectural pattern,