This chapter provides a comprehensive overview of the
pathological and immunophenotypic characterisation of canine splenic lymphoma,
focusing on detailed diagnostic approaches and subtyping through integrated
analysis of gross, cytological, histopathological, and immunohistochemical
features in both biopsy and necropsy specimens.
Background: Lymphoma constitutes the third most common
malignant neoplasm, accounting for approximately 7-24% of all canine neoplasms
and 83% of all canine hematopoietic malignancies. The aetiology of canine
lymphoma (cL) is multifactorial, and environmental factors play a pivotal role.
Aim: This study aimed to characterise canine splenic
lymphoma through a comprehensive evaluation of gross, cytological,
histopathological, and immunophenotypic features in both biopsy and necropsy
specimens, and to distinguish primary splenic lymphomas from splenic
involvement in multicentric disease.
Methodology: The study was conducted in the Department of
Veterinary Pathology, Madras Veterinary College, India, for one year (June 2011
to June 2012). An observational, descriptive investigation was undertaken on
confirmed cases of canine splenic lymphoma submitted for routine diagnostic
evaluation. Eight canine cases were diagnosed as splenic lymphoma, comprising
six multicentric diffuse large B-cell lymphomas (DLBCL) and two primary splenic
B-cell lymphoblastic lymphomas (B-LBL). Specimens were obtained from surgically
excised splenic biopsies and post-mortem examinations. Grossly, all spleens
exhibited marked splenomegaly, with weights ranging from 120 to 560 g. Patient
data revealed a mean age of 8.56 years, with no sex predilection and
representation from multiple breeds. Cytological and histopathological
classification was performed according to the updated Kiel and World Health
Organisation (WHO) criteria. Immunohistochemical analysis employed a Pan T-cell
marker (CD3) and a B-cell marker (CD79a) to determine lineage.
Results: The age recorded in this study ranges from 3.5 to
12 years with mean of 8.2 years, and found equal distribution of sex. All cases
demonstrated a CD3-negative/CD79a-positive immunophenotype, consistent with
high-grade B-cell lymphoma. Six cases represented splenic involvement in
multicentric lymphoma, whereas two were classified as primary splenic
lymphomas. The cytological study of lymphoma revealed a homogenous clonal population
of lymphoblasts with lymphoglandular bodies with variation in multiple nucleoli
and scanty basophilic cytoplasm. Histology showed the white and red pulps were
completely substituted by B-LBL neoplastic cells. Cells showed anisokaryosis,
prominent nuclei, and chromatin margination. Neoplastic cell showing nuclear
indentation with a large, single, prominent nucleolus. Histomorphological
features corresponded to their cytological classification, and gross lesions
were characterised by diffuse enlargement and loss of normal splenic
architecture.
Conclusion: The integration of gross pathology, cytology,
histopathology, and immunohistochemistry enables accurate subtyping of canine
splenic lymphoma, with CD3 and CD79a serving as reliable markers for lineage determination.
In this series, high-grade B-cell lymphoma was the predominant subtype,
underscoring its clinical relevance and the value of immunophenotyping in
routine diagnostic practice. Canine lymphoma is a treatable neoplasm with
single-agent or multiple-agent chemotherapy; thus, the early diagnosis ensures
longer survivability with appropriate therapy.
Author(s) Details
Mohanapriya, T
Department of Veterinary Pathology, Veterinary College, Salem, India.
M. Thangapandiyan
PDDSL, Namakkal, India.
R. Sridhar
Central University Laboratory, Madhavaram, Chennai, India.
Please see the book here :- https://doi.org/10.9734/bpi/msup/v2/6542
