Two Hundred Three Cases of Equine Lymphoma Classified According to the World Health Organization (WHO) Classification Criteria

Abstract

Lymphoma is the most common malignant neoplasm in the horse. Single case reports and small retrospective studies of equine lymphomas are reported infrequently in the literature. A wide range of clinical presentations, tumor subtypes, and outcomes have been described, and the diversity of the results demonstrates the need to better define lymphomas in horses. As part of an initiative of the Veterinary Cooperative Oncology Group, 203 cases of equine lymphoma have been gathered from 8 institutions. Hematoxylin and eosin slides from each case were reviewed and 187 cases were immunophenotyped and categorized according to the World Health Organization classification system. Data regarding signalment, clinical presentation, and tumor topography were also examined. Ages ranged from 2 months to 31 years (mean, 10.7 years). Twenty-four breeds were represented; Quarterhorses were the most common breed (n = 55), followed by Thoroughbreds (n = 33) and Standardbreds (n = 30). Lymphomas were categorized into 13 anatomic sites. Multicentric lymphomas were common (n = 83), as were skin (n = 38) and gastrointestinal tract (n = 24). A total of 14 lymphoma subtypes were identified. T-cell-rich large B-cell lymphomas were the most common subtype, diagnosed in 87 horses. Peripheral T-cell lymphomas (n = 45) and diffuse large B-cell lymphomas (n = 26) were also frequently diagnosed.

Linfoma mediastinal em equino - relato de caso

“…Algumas horas após retornar a baia, o animal veio a óbito. (Durham et al, 2012). Essa forma de linfoma pode ser de difícil classificação no exame citológico da efusão pleural ou no exame histopatológico, uma vez que apresenta população de linfócitos neoplásicos associados a linfócitos maduros, caracterizando uma população heterogênea.…”

“…O linfoma, também conhecido por linfoma maligno ou linfossarcoma, é a neoplasia hematopoiética mais comumente encontrada em equinos (Mair et al, 1985;Meyer et al, 2006;Muñoz et al, 2009;Durham et al, 2012), no entanto é considerado raro quando se compara sua ocorrência em outras espécies (Taintor e Schleis, 2011). Esse tumor tem sido classificado em multicêntrico ou generalizado, alimentar, mediastinal, cutâneo (Mair et al, 1985;Mair e Brown, 1993;Muñoz et al, 2009) e isolado (Muñoz et al, 2009;Taintor e Schleis, 2011).…”

Classification and clinical features in 88 cases of equine cutaneous lymphoma

“…For cases submitted to Ontario Veterinary College, University of Wisconsin at Madison, University of Florida, University of Illinois, Ohio State University, and University of Pennsylvania, IHC was performed as previously described. 4 Each case was then classified into the lymphoma subtypes listed above according to the veterinary-adapted WHO classification system as previously described. 4,17,18 Histology submission forms, medical records, and diagnostic reports were reviewed for clinical and histological information.…”

“…The objective of this retrospective study was to evaluate previously diagnosed cases of equine cutaneous lymphoma, classify them by subtype using the veterinary-adapted WHO classification system, and correlate these findings with available clinical data to identify both epidemiological trends and prognostic features. A retrospective review was performed on cases of previously diagnosed cutaneous lymphoma from 1999 to 2010 that had been identified by Schaffer et al 12 (n = 50) and Durham et al 4 (n = 33) and by additional query of laboratory 561653V DIXXX10.1177/1040638714561653Classification and clinical features of equine cutaneous lymphomaMiller et al…”

Advanced multicentric lymphoma in a Belgian Draft Horse mare

“…Multicentric lymphoma is the most common form in horses, accounting for approximately 40 % of lymphoma cases (Durham et al 2013, Ness 2016, Taintor and Schleis 2011. Multicentric lymphoma is characterised by widespread involvement of peripheral lymph nodes and a variety of abdominal, thoracic and other organs (Taintor and Schleis 2011).…”