Topic:Lymphoma
Lymphoma in horses is a type of cancer that originates in the lymphoid tissues, which are part of the immune system. It involves the uncontrolled proliferation of lymphocytes, a type of white blood cell. Lymphoma can affect various organs and systems in horses, including the lymph nodes, spleen, liver, gastrointestinal tract, and skin. Clinical signs may vary depending on the location and extent of the disease, and may include weight loss, lethargy, swelling of lymph nodes, and abnormal blood work. Diagnosis often involves a combination of clinical examination, imaging, and biopsy. This page compiles peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment options, and prognosis of lymphoma in equine patients.
Primary epitheliotropic intestinal T-cell lymphoma as a cause of diarrhea in a horse. A 25-year-old Appaloosa gelding was evaluated for chronic weight loss and diarrhea. A clinical diagnosis of protein loosing enteropathy was made and the gelding was euthanized. Histology revealed neoplastic lymphocytes infiltrating the mucosa of the small and large intestine. Immunohistochemistry was positive for CD3, consistent with epitheliotropic T-cell lymphoma. Lymphome T intestinal épithéliotrope primaire comme cause de diarrhée chez un cheval. Un hongre appaloosa âgé de 25 ans a été évalué pour perte de poids et diarrhée chronique. Un diagnostic clinique d’entéropathie avec...
Radiation therapy communication: nasal passage and paranasal sinus lymphoma in a pony. An aged pony with extensive paranasal sinus and nasal passage B-cell lymphoma was treated with palliative radiation therapy. Sixteen gray were administered in two fractions, 7 days apart. A lateral field was used for the first fraction and a dorsal field for the second. Because of tumor being present in the left frontal sinus, gross tumor was knowingly excluded from the treated volume in the lateral field. The tumor regressed within 2 months and the pony remained free of clinical disease for 2.5 years. Acute, temporary blindness developed shortly after the second radiation fraction, but a dire...
Hematopoietic neoplasias in horses: myeloproliferative and lymphoproliferative disorders. Leukemia, i.e., the neoplasia of one or more cell lines of the bone marrow, although less common than in other species, it is also reported in horses. Leukemia can be classified according to the affected cells (myeloproliferative or lymphoproliferative disorders), evolution of clinical signs (acute or chronic) and the presence or lack of abnormal cells in peripheral blood (leukemic, subleukemic and aleukemic leukemia). The main myeloproliferative disorders in horses are malignant histiocytosis and myeloid leukemia, the latter being classified as monocytic and myelomonocytic, granulocytic, prim...
Pelvic lymphoma as a cause of urethral compression in a mare. A 6-year-old mare was presented for evaluation of dysuria and pollakiuria. A pelvic mass, which caused obstruction of urinary outflow, was identified. Evidence of renal failure was also present. Due to poor prognosis the mare was euthanized. A postmortem examination revealed a pelvic lymphoma that surrounded and compressed the urethra. Lymphome pelvien comme cause de compression urétrale chez une jument. Une jument âgée de 6 ans est présentée pour évaluation de dysurie et de pollakiurie. Une masse pelvienne qui causait l’obstruction de l’écoulement d’urine a été identifiée. Des...
Gastric neoplasia in horses. Gastric neoplasia of horses is incompletely described. Objective: Provide history, clinical signs, and clinicopathological and pathological findings associated with gastric neoplasia in horses. Methods: Twenty-four horses with gastric neoplasia. Methods: Retrospective study. History, clinical signs, and clinicopathological and pathologic findings in horses diagnosed histologically with gastric neoplasia were reviewed. Results: Horses ranged in age from 9 to 25 years (median 18 years at presentation). There was no apparent breed or sex predisposition. The most common presenting complaints were ...
Ocular and multicentric lymphoma in a young racehorse. A 6-year-old thoroughbred gelding was presented with a history of blepharospasm and opacity in the OS of 1 weeks' duration. Ophthalmic examination findings were consistent with acute uveitis in the OS, and traditional treatment was initiated with systemic antibiotics and anti-inflammatory drugs, topical mydriatics, and corticosteroids. During the total treatment period of 4 weeks response to treatment was weak and the horse developed further problems such as cellulitis of the right hind limb with fever and eventually weight loss and dependent edema. Blood work was indicative of liver disease. ...
Bone marrow necrosis and myelophthisis: manifestations of T-cell lymphoma in a horse. A 14-year-old spayed American Paint mare was evaluated for mild colic, anorexia, pyrexia, and pancytopenia. Physical examination revealed mild tachycardia, tachypnea, and pale mucous membranes. Serial laboratory analyses revealed progressive pancytopenia, hyperfibrinogenemia, and hyperglobulinemia. A few large atypical cells were observed in peripheral blood smears. Results of tests for equine infectious anemia and antipenicillin antibody were negative. Serum protein electrophoresis indicated a polyclonal gammopathy. Smears of bone marrow aspirates contained hypercellular particles, but cell l...
Mediastinal lymphoma with complete atrioventricular block in a horse. A 15-year-old, neutered-male pony presented with a history of weight loss during 4 months. Clinical evaluation revealed severe bradycardia and complete atrioventricular block. At necropsy, a lobulated mass in the anterior mediastinum and moderate enlargement of the superficial cervical lymph nodes were observed. The vagus nerve and the brachiocephalic trunk were embedded in this anterior mediastinal tumor. Histologically, the mass was composed of sheets of neoplastic lymphoid cells expressing CD3, with a low mitotic rate. To the best of our knowledge, this is the first reported case of mediast...
Lymphoproliferative disease with features of lymphoma in the central nervous system of a horse. Lymphoma (malignant lymphoma, lymphosarcoma) is uncommon in horses in the United Kingdom. This report describes an unusual form of lymphoproliferative disease with features of lymphoma restricted to the central nervous system (CNS) and with no evidence of a primary lesion elsewhere. Immunohistochemical examination defined an overwhelming predominance of T lymphocytes with admixed B lymphocytes and activated macrophages. This case exemplifies the challenges associated with definitive diagnosis of lymphoproliferative disease of the equine CNS.
Clinical, immunophenotypic and functional characterisation of T-cell leukaemia in six horses. Lymphoid leukaemia (LL) is rare in equids. In man, immunophenotypic classification identifies distinct leukaemic types with different treatment strategies. Improved understanding and classification of equine LL may allow similar advances. Objective: To document the clinical, immunophenotypic and functional characteristics in 6 cases of equine LL of T-cell origin. Methods: The clinical records and pathological findings from 6 cases of equine LL were analysed. Immunohistochemistry to identify T or B lymphocytes was performed on paraffin embedded tissues in 4 cases. Peripheral blood mononuclear c...
Long-term outcome associated with intratumoral chemotherapy with cisplatin for cutaneous tumors in equidae: 573 cases (1995-2004). To determine outcome associated with cutaneous tumors treated via intratumoral chemotherapy with cisplatin and identify risk factors affecting local tumor control and complications in equidae. Methods: Retrospective case series. Methods: 573 equidae with 630 cutaneous tumors. Methods: Medical records of horses, mules, donkeys, and ponies with cutaneous tumors treated via intratumoral chemotherapy with cisplatin were analyzed. Results: 549 horses, 13 mules, 8 donkeys, and 3 ponies with 630 histologically confirmed cutaneous tumors were included. Tumors included sarcoids (n = 409), squamous cell...
Hypertrichosis in a horse with alimentary T-cell lymphoma and pituitary involvement. A 13-year-old Quarterhorse mare had a 6-month history of diarrhea, progressive weight loss, and lethargy. At presentation the mare was hirsute, had hyperhidrosis, and abnormal fat distribution in addition to severe diarrhea. A presumptive clinical diagnosis of protein-losing enteropathy and pituitary pars intermedia dysfunction was made. T-cell lymphoma was diagnosed in a rectal biopsy specimen. The owner elected to euthanize the mare because of poor prognosis and the severity of the disease. At necropsy, the mare had hypertrichosis and the pituitary gland was diffusely enlarged. Histologicall...
Clinical, histopathological and immunophenotypical findings in five horses with cutaneous malignant lymphoma. This study documents the clinical, histopathological, immunohistochemical and flow-cytometric findings in five horses with cutaneous non-epidermotropic malignant lymphoma (ML). The median survival time after discovery of the first subcutaneous nodules was 3.8 years (range 2-5 years: n=4). Histologically, the cutaneous ML had a pleiomorphic structure and contained a mixture of large reticulo-endothelial cells, medium-large sized lymphoid cells with a rounded nucleus and small nucleoli, many medium sized lymphoid cells with irregular nuclei, and some small lymphoid cells. Immunohistochemically (...
Clinical, laboratory, and histopathologic features of equine lymphoma. Clinical, laboratory and tissue findings from 37 horses with lymphoma were investigated. Horses ranged in age from 0.3 to 20.5 years (median 5.0 years) and included 18 females and 19 males. Weight loss (n = 25) and ventral edema (n = 21) were the most common historical and physical abnormalities. The most common laboratory abnormalities were hyperfibrinogenemia (n = 26), hypoalbuminemia (n = 19), anemia (n = 19), leukemia (n = 14), hyperglobulinemia (n = 13), and thrombocytopenia (n = 13). Thirty-four tumors involved multiple lymphoid tissues and abdominal or thoracic organs, and 3 tumors were...
Cutaneous lymphosarcoma in a stallion. Multiple cutaneous lymphosarcomas were diagnosed in an 8-year-old Thoroughbred stallion presented for evaluation of lumps on its scrotum. Histological examination of skin biopsy samples showed a homogenous pattern of lymphoid tissue suggestive of a T-cell lymphosarcoma. Immuno-histochemical tests showed a positive reaction to Rabbit/Anti-Human T-Cell, CD3 antibodies confirming T-cell lymphosarcoma. The animal was not treated and was subsequently euthanased.
Sudden death due to thoracic lymphoma in a standardbred racing horse. During training, a 6-year-old standardbred gelding collapsed, exhibiting severe epistaxis and agonal breathing and was euthanized. The horse had a recent history of poor performance, lethargy, and unilateral eyelid swelling with serous ocular discharge. Postmortem and histopathologic examination findings revealed thoracic lymphosarcoma and concurrent exercise-induced pulmonary hemorrhage. Résumé — Mort subite d’un cheval de course de race standardbred causée par un lymphome thoracique. En cours d’entraînement, un standardbred hongre âgé de 6 ans s’est effondré, présentant des s...
Metastatic tumors to the adrenal glands in domestic animals. Although metastases to the adrenals are common in humans, they have not been thoroughly studied in animals. The purpose of this retrospective study was to document the types of malignant tumors that metastasize to canine, feline, equine, and bovine adrenals, and the rate at which they do so. The average rate of adrenal involvement in metastatic cancer was 112/534 (21.0%) in dogs, 12/81 (14.8%) in cats, 18/67 (26.9%) in horses, and 5/16 (31.3%) in cattle. In dogs, 26 different tumor types metastasized to the adrenals. Pulmonary, mammary, prostatic, gastric, and pancreatic carcinomas, and melano...
Ultrasound-guided biopsy as a diagnostic aid in three horses with a cranial mediastinal lymphosarcoma. An ultrasound examination of the thorax of three horses which were performing poorly or had mild signs of colic showed that they had a cranial mediastinal mass and a pleural effusion. A cytological examination of the pleural fluid showed that it did not contain neoplastic cells. A histological examination of an ultrasound-guided core biopsy of the cranial mediastinal mass showed that in each of the three horses it was a lymphosarcoma.
Use of chemotherapy for treatment of a mixed-cell thoracic lymphoma in a horse. A 4-year-old Oldenburg mare was evaluated because of signs of lower airway disease and subsequently developed bilateral pleural effusion. Neoplastic cells were not identified in the fluid sample obtained via the initial thoracocentesis. A thoracic mass was detected radiographically, but its location prevented collection of a tissue sample. A diagnosis of lymphoma was made on the basis of results of immunophenotyping of pleural fluid specimens. Treatment of thoracic lymphoma in horses has been attempted, but there are limited data regarding chemotherapeutic-induced remission. In this horse, rem...
Serum IgM concentrations in normal, fit horses and horses with lymphoma or other medical conditions. The purposes of this study were to (1) prospectively establish serum IgM and IgG concentrations in normal, fit, adult horses over time and (2) determine the accuracy of serum IgM concentrations for diagnosing lymphoma. Serial IgM and IgG concentrations were measured with a radial immunodiffusion assay in 25 regularly exercised horses at 6-week intervals. Horses had serum IgM concentrations ranging from 50 to 242 mg/dL over 5 months, with 20% of horses having IgM < or = 60 mg/dL. The normal range for IgM in fit horses should be considered 103 +/- 40 mg/dL and a cut-point for an IgM deficiency, ...
Extranodal lymphoblastic lymphoma of suspected B-cell lineage in the gingiva of a racehorse, accompanied by mandibular osteolysis. A mass developed in the mandibular gingiva of a thoroughbred racehorse. When the horse could no longer eat unassisted, it was killed and immediately autopsied. Macroscopically, the mandible exhibited extensive osteolysis, with only a small amount of bone remaining around the tooth roots. The cut surface of the mass around the mandible consisted of neoplastic medullary tissue, in which osteogenesis was observed. The medullary tissue was composed of pleomorphic medium-sized to large cells, interlaced by collagen bundles. These cells had large, pale, round or ovoid, sometimes cleaved nuclei, with...
Hepatosplenic T-cell lymphoma in a mare. A 21-year-old Dutch crossbred mare was presented with a 1-month history of weight loss and weakness. Clinical evaluation revealed severe anemia and thrombocytopenia with evidence of hepatic disease and muscular damage. Necropsy findings included diaphragmatic rupture with an extensive retroperitoneal hematoma and severe hepatosplenomegaly. Microscopic findings were characterized by hepatic sinusoidal and splenic red pulp infiltration by atypical CD3-positive lymphocytes. No other nodal or extranodal sites were affected. Hepatosplenic lymphoma with a probable T-cell origin was diagnosed based o...
Immunohistochemical characterization of estrogen and progesterone receptors in lymphoma of horses. Immunohistochemical techniques were used to examine 29 cases of equine lymphoma for estrogen receptor (ER) and progesterone receptor (PR) expression. The lymphomas examined included T-cell-rich large B-cell lymphomas, B-cell neoplasms, and T-cell lymphomas. The individual cases were also classified according to the anatomic location of the tumors. One normal equine lymph node was also examined for ER and PR expression. All of the cases of equine lymphoma and the normal lymph node were negative for Er. A total of 16/29 (55%) PR-positive lymphomas were identified. Seven of the 12 (58%) T-cell-ri...