Equine lymphoma

Advanced multicentric lymphoma in a Belgian Draft Horse mare

“…Lymphoma is the most common malignant hematopoietic neoplasm in the horse (Muñoz et al 2009, Janvier et al 2016, Ness 2016, with a reported incidence of between 1% and 3 % of all equine tumours (Janvier et al 2016, Taintor andSchleis 2011). Equine lymphoma arises from lymphoid tissue and is conventionally categorized according to the distribution of tumour lesions as alimentary, cutaneous, mediastinal or multicentric (Schwarz et al 2012, Ness 2016, Taintor and Schleis 2011.…”

“…Equine lymphoma arises from lymphoid tissue and is conventionally categorized according to the distribution of tumour lesions as alimentary, cutaneous, mediastinal or multicentric (Schwarz et al 2012, Ness 2016, Taintor and Schleis 2011.…”

“…Although lymphoma may develop at any age most cases are reported in horses 4 to 10 years of age (Muñoz et al 2009, Taintor andSchleis 2011). The clinical signs are often nonspecific and depend upon the type of tumour and the affected organ(s) (Janvier et al 2016, Ness 2016.…”

“…The clinical signs are often nonspecific and depend upon the type of tumour and the affected organ(s) (Janvier et al 2016, Ness 2016. Paraneoplastic syndromes are often the earliest detectable evidence of lymphoma and may include generalised pruritus, undulant pyrexia, cachexia, hypercalcemia and erythrocytosis (Axiak andJohnson 2011, Taintor andSchleis 2011). The total white blood cell count (WBC) is seldom diagnostically helpful since most cases of equine lymphoma are non-leukaemic (Ness 2016).…”

“…Leukaemia may be primary when the neoplasm originates in the bone marrow and neoplastic cells are released into the peripheral circulation. Secondary leukaemia occurs when lymphoma has metastasized to the bone marrow producing a myelophthisic state (Cian et al 2013, Ness 2016, Taintor and Schleis 2011. Leukaemia can be classified by the cell of origin as myeloproliferative or lymphoproliferative, and by maturation stage as acute (blast cells in the circulation) or chronic (mature differentiated cells in the circulation).…”