Sarcoma in horses refers to a group of malignant tumors that arise from connective tissues, including bone, cartilage, fat, muscle, and blood vessels. These tumors can develop in various parts of the horse's body and may differ in their behavior, growth rate, and response to treatment. Common types of sarcomas in horses include fibrosarcoma, osteosarcoma, and hemangiosarcoma. The diagnosis of sarcoma typically involves a combination of clinical examination, imaging techniques, and histopathological analysis. Treatment options may vary depending on the type and location of the tumor and can include surgical excision, chemotherapy, or radiation therapy. This page compiles peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, and treatment of sarcomas in equine patients.
MacGillivray KC, Graham TD, Parente EJ.A 2-year-old male Thoroughbred was evaluated for multiple firm, raised nodules of the maxilla and mandible that had been present since 6 months of age. The horse was evaluated as a yearling with a final histologic diagnosis of fibrosarcoma. As a 2-year-old, the colt made a loud upper airway sound and was agitated after strenuous exercise. Results of upper airway endoscopy indicated severe narrowing of the nasal passages and pharynx with normal resting function. Radiography revealed multiple circular bony lesions in the mandible, maxilla, multiple long bones, and cervical vertebrae. Biopsy spec...
Teifke JP, Kidney BA, Löhr CV, Yager JA.We examined 12 formalin-fixed paraffin-embedded feline skin tumours which had the histopathological features of fibropapillomas for the presence of papillomavirus (PV) DNA using touchdown polymerase chain reaction (PCR), DNA sequencing and nonradioactive in situ hybridization. Nine of the tumours contained a 102-bp PCR product demonstrated using consensus PV primers that amplify a portion of the L1 gene. The nucleotide sequences are closely related, but not identical to that of ovine PV type 2, rabbit oral PV and reindeer PV. The deduced amino acid sequences had strong homologies with the majo...
Sanchez B, Nieto A, de Ruiz Leon MA, Rodríguez J, Flores J.A lymphangiosarcoma with metastases was found in a horse that presented with respiratory distress and edema in the ventral thorax and abdomen. The necropsy revealed diffuse edema in the subcutaneous connective tissue. Mediastinal, mesenteric, iliac, and renal lymph nodes were enlarged and white with soft, yellowish necrotic areas. Histologic examination revealed numerous channels and disorganized vessels lined by large polyhedral, polymorphic cells. Tumor metastases were observed in the spleen, lungs, and kidneys. Immunohistochemical evaluation of the tumor cells demonstrated positive staining...
Strubbe DT.A periocular neurofibrosarcoma was debulked and treated with intralesional cisplatin in a 5-year-old Thoroughbred mare. The horse presented with a 1-year history of a large slowly progressing subcutaneous mass over the right supraorbital process. The mass was surgically debulked, and intralesional cisplatin (1.0 mg/cm3) was injected in 3 doses at 2 weeks, 5 weeks, and 8 weeks postoperatively. No recurrence was noted over a 15-month follow-up period. Histopathology of the mass indicated neurofibrosarcoma.
IJzer J, van den Ingh TS.A 15-year-old Dutch Warmblood mare presented with respiratory distress and anorexia. Clinical examination revealed liquothorax and an abdominal mass. At necropsy, an infiltrating tumour was found in the visceral trunk, continuing through the diaphragm into the mediastinum. Histopathology, immunohistochemistry and electronmicroscopy showed empty channels lined by atypical endothelial cells, and neoplastic cells in a disorganized pattern, consistent with the diagnosis of a lymphangiosarcoma.
Southwood LL, Schott HC, Henry CJ, Kennedy FA, Hines MT, Geor RJ, Hassel DM.Thirty-five cases of disseminated hemangiosarcoma (21 clinical cases and 14 previously reported cases) were reviewed to describe the disease in horses. Hemangiosarcoma occurred in mature, particularly middle-aged horses, with no apparent sex predilection. Thoroughbreds seemed to be overrepresented (13 cases) but a true breed predilection could not be established. The respiratory and musculoskeletal systems were most commonly affected and presenting complaints included dyspnea (26%), subcutaneous or muscular swelling (24%), epistaxis (17%), and lameness (12%). Heart and respiratory rates were u...
Berry S.Hemangiosarcoma in the spinal canal was diagnosed in a 25-year-old stallion showing progressive and symmetrical 4-limb ataxia, proprioceptive deficits, and weakness. On necropsy, an extradural mass consisting of spindle-shaped cells and numerous free erythrocytes was found at the level of C7-T1. Immunohistochemical staining confirmed a neoplasm of endothelial origin.
Roels S, Ducatelle R, van De Vijver B, De Kruif A.An 18-month-old cross-bred Fjord pony colt presenting a fibrosarcoma of the prepuce with severe infiltrative growth, was treated by topical application of 5-fluorouracil. Biopsies were taken before and after a treatment period of 2 months. As a control, preputial tissue from a healthy horse was biopsied. Tissue sections were stained immunohistochemically for Proliferating Cell Nuclear Antigen (PCNA) and Proliferation related factor--Ki67 (MIB1). Using computerized quantitative image analysis of these sections, Mitotic index (PCNA), Growth Fraction (Ki67) and total nuclear area percentage of th...
Kofler J, Kübber-Heiss A, Schilcher F.Clinical, ultrasonographic and pathological findings of a cutaneous, multilocular T-cell lymphosarcoma (malignant lymphoma) in a 13-year-old, brown Austrian warmblood mare are reported. The horse was under clinical observation, and the tumours were sonographically monitored over an 8 month period, revealing worsening of body condition, weight loss, lameness of the left hindlimb and a slight increase in the tumours size. Most of the tumours were covered by normal skin, one showed ulceration. Ultrasonography of the tumours allowed accurate anatomical localization in relation to the adjoining tis...
Newton-Clarke MJ, Guffoy MR, Dykes NL, Divers TJ.A haemangiosarcoma in a horse resulted in ataxia affecting all four legs, a low head carriage and a reluctance to flex the neck. Ancillary diagnostic procedures included the analysis of cerebrospinal fluid, standing lateral cervical radiographs and a myelogram. Post mortem a tumour was found which involved the body of the second cervical vertebra and the associated hypaxial muscles, with secondary intravertebral extradural infiltration and focal compressive myelopathy. A histological examination showed that the tumour was a haemangiosarcoma.
Bloch N, Breen M, Spradbrow PB.Seventy six formalin-fixed paraffin-embedded sarcoids from 62 Australian horses, collected over a ten year period, were examined for the presence of genomic sequences from bovine papillomavirus 1 and 2 (BPV1, BPV2) with the polymerase chain reaction (PCR). Sequences that could be amplified by primers specific for BPV1 and BPV2 were present in 56 of the 76 sarcoids (73%). A restriction site present in BPV1 and absent from BPV2 was detected in 28 of 34 amplified products that were treated with endonuclease.
Hanson PD, Frisbie DD, Dubielzig RR, Markel MD.A 5-year-old Quarter Horse mare was examined because of a 6-month history of quidding and nasal discharge that contained feed material. Physical examination revealed weight loss and dorsal displacement of the soft palate, caused by a soft tissue mass located at the dorsal aspect of the base of the tongue. Surgical resection of the mass was successfully performed through an oral approach. The histopathologic diagnosis was rhabdomyosarcoma.
Okada K, Okada M, Yamamoto S, Mukai T, Tsukube T, Matsuda H, Okada M.We successfully performed a total resection of the pulmonary artery trunk and replaced it with an equine pericardial xenograft roll in a patient with a recurrent leiomyosarcoma. We believe, based on anatomic and embryologic principles, total rather than partial resection of the pulmonary artery trunk should be the treatment of choice for primary leiomyosarcomas of the pulmonary artery.
Danton CA, Peacock PJ, May SA, Kelly DF.A 16-year-old showjumping gelding was examined because of a non-painful, slowly progressive caudal thigh swelling, which was associated with 2/10th lameness at the trot. Radiography, real time beta-mode ultrasonography and gamma-scintigraphy of the caudal thigh for the presence of chip fractures, sequestrum formation and, or, abscessation were inconclusive. Radiographic examination of the chest revealed multifocal, nodular cannon ball-like opacities throughout the entire lung fields from which a diagnosis of a primary soft tissue tumour with metastasis to the thorax was made. An anaplastic sar...
Boy MG, Palmer JE, Heyer G, Hamir AN.Gastric leiomyosarcoma was diagnosed in a 12-year-old Thoroughbred gelding. The horse was examined because of anorexia, weight loss, and intermittent fever of 1.5 months' duration. Antemortem diagnostic testing was extensive, but a definitive diagnosis could not be reached with noninvasive methods. Exploratory celiotomy confirmed an intra-abdominal mass, and the horse was euthanatized. Necropsy revealed a firm mass associated with the distal portion of the esophagus, cranial two thirds of the stomach, and visceral surface of the liver. The histopathologic diagnosis was leiomyosarcoma.
Edens LM, Taylor DD, Murray MJ, Spurlock GH, Anver MR.A large fibrotic mass originating from the cecal base was discovered upon surgical exploration of the abdomen in a Thoroughbred mare with a history of chronic colic and weight loss. The mass protruded intraluminally resulting in partial obstruction. Surgical excision was not feasible due to the location of the mass and the inability to exteriorize it adequately from the abdominal cavity. The mass was fibrous with a shiny, gelatinous material present throughout the neoplasm. Histologically, large confluent spaces filled with mucopolysaccharides were identified by staining with Alcian blue. The ...
Sweeney RW, Hamir AN, Fisher RR.A 9-year-old Thoroughbred mare was examined because of pollakiuria, hematuria, and weight loss of 3 weeks' duration. Physical examination revealed a regular cardiac rhythm with occasional premature contractions, and a soft tissue mass in the pelvic canal palpable per rectum. Microscopic examination of urine sediment revealed numerous RBC and a large population of lymphocytes and lymphoblasts with characteristics of neoplasia. Similar cells were found in peritoneal fluid obtained by abdominocentesis. The horse was euthanatized without treatment. Necropsy revealed a soft tissue mass infiltrating...
Anderson WI, Scott DW, Crameri FM.Two rare equine cutaneous neoplasms, an apocrine gland adenocarcinoma and a carcinosarcoma were diagnosed in a 17-year-old pony and a 14-year-old mare, respectively. The apocrine gland adenocarcinoma was present on the prepuce. Histologically, papillary projections of low cuboidal to columnar epithelial cells were generally well differentiated, and surrounded dilated acini. Stromal invasion was present, but vascular and lymphatic invasion was not seen. The carcinosarcoma was present in the right flank of the mare. Two discrete cell populations were characterized histologically. One portion of ...
Frauenfelder HC, Blevins WE, Page EH.Twelve periocular fibrous connective tissue sarcomas in 11 horses were treated with 222Rn. Follow-up periods ranged from 1 to 6 years; the overall nonrecurrence rate at 12 months after therapy was 92%. Two lesions recurred 2 years after treatment, and 1 after 3 years. One of the former lesions has not recurred after a 2nd 222Rn treatment.
Biegel U, Mevissen M, Schuller S, Ruess K, Christen O, Ayrle H, Koch C, Walkenhorst M.Cancer is a common disease in humans and in companion animals and treatment is challenging. The aim of this systematic review was to identify and assess the potential use of Viscum album L. extracts (VAE) for treatment of neoplastic diseases in companion animals. Peer-reviewed animal, in vivo and in vitro studies were included, considering the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and A Measurement Tool to Assess Systematic Reviews (AMSTAR). Overall, 6,148 references were identified. Following a predefined protocol, 114 full-text references were ...
Arenas-Gamboa AM, Mansell J.Haemangiosarcomas (HSAs) are malignant tumours of endothelial cell origin. Epithelioid HSA is a variant of the histologically conventional HSA that has little or no morphological evidence of a vascular origin and has been reported rarely in domestic animals. The following report documents six cases of equine epithelioid HSA occurring in the ocular tissues of horses with a mean age of 19.8 years at the time of diagnosis. Microscopically, all of the lesions consisted of solid sheets or cords of epithelioid cells with rare narrow clefts or small spaces containing erythrocytes that were often the ...
Paciello O, Passantino G, Costagliola A, Papparella S, Perillo A.Histiocytic diseases in veterinary medicine have been revised in the last few decades, but these are considered relatively rare in horses. This report describes a 9-year-old female horse, Dutch Warmblood, presented for investigation of severe nasal bleeding. A multinodular bilateral mass of 5 cm, reddish to white in color, that invaded and destroyed the surrounding tissues, was observed during a clinical examination of the nostril The morphological features of the tumor cells were represented by cytologically bizarre, highly phagocytic, multinucleated giant cells. These findings, together with...
Sheahan BJ, Atkins GJ, Russell RJ, O'Connor JP.Two aged mares with histiolymphocytic lymphosarcoma had multiple rapidly proliferating tumours in the subcutis. Consistent haematological changes were absent. One mare had lymph node involvement but no neoplastic lesions in the viscera. Microbiological examination of tumour tissue showed coryneform bacteria; there was no evidence of C-type or lytic viruses or of reverse transcriptase. Prominent intramitochondrial crystalline inclusions were in histiocytic tumour cells.
Puff C, Herder V, Philipp A, Baumgärtner W.A 15-year-old Haflinger gelding presented with a mass in the left nictitating membrane. Two biopsies and the excised nictitating membrane were taken at different time points as a result of reoccurrence of the mass and submitted for histopathologic evaluation. The horse was euthanized as a result of poor prognosis following the reoccurrence of the mass after surgical removal. Histologically, the mass consisted of dilated, thin-walled vascular clefts and channels, lined by flattened to cuboidal endothelial cells with moderate cellular pleomorphism. There was up to 1 mitotic figure per high power...
IJzer J, van den Ingh TS.A 15-year-old Dutch Warmblood mare presented with respiratory distress and anorexia. Clinical examination revealed liquothorax and an abdominal mass. At necropsy, an infiltrating tumour was found in the visceral trunk, continuing through the diaphragm into the mediastinum. Histopathology, immunohistochemistry and electronmicroscopy showed empty channels lined by atypical endothelial cells, and neoplastic cells in a disorganized pattern, consistent with the diagnosis of a lymphangiosarcoma.
Snook ER, Wakamatsu N.A 17-year-old, Thoroughbred mare was presented for necropsy with a large, invasive oral mass determined via immunohistochemistry to be a soft tissue sarcoma of neural origin. Oral sarcomas are rare in veterinary medicine, and to the authors' knowledge, this is the first oral sarcoma of neural tissue origin reported in a horse.
Bogaert L, Heerden MV, Cock HE, Martens A, Chiers K.Ten equine skin tumors that had been classified as schwannomas on routine histological examination were analyzed by polymerase chain reaction for bovine papillomavirus DNA. All 10 were positive for bovine papillomavirus 1 or 2, and all 10 were immunohistochemically negative for S-100 protein and strongly positive for vimentin. Nine tumors were moderately positive for laminin and 8, for smooth muscle actin. Five tumors were variably and weakly positive for type IV collagen. The lack of S-100 protein expression made Schwann cells an unlikely cell of origin, as opposed to peripheral nerve sheath ...
Ishigami N, Horiba K.A 41-year-old woman presented with symptoms of cardiac tamponade. Diagnosis of a primary malignant tumor in the right atrium without distant metastasis was made by echocardiography, computed tomography and coronary angiography. Aggressive surgery consisting of resection of the tumor including the right atrial wall together with the right coronary artery and sinus node was performed. This was followed by coronary artery bypass grafting with myocardial electrode implantation for reconstruction of the right atrial wall using an equine pericardium. Final diagnosis was of angiosarcoma by pathologic...
Johnson JE, Beech J, Saik JE.A 6.5-year-old horse with a history of exercise-induced pulmonary hemorrhage was admitted because of acute onset of epistaxis, dyspnea, high respiratory rate, pale mucous membranes, and dark feces. There was no clinical or laboratory evidence of a bleeding disorder, and the horse's anemia was considered to be secondary to pulmonary hemorrhage. The cause of the hemorrhage was not found on thoracic sonograms or from cytologic examination of transtracheal aspirates. Despite supportive care, the horse's health deteriorated, and it was euthanatized. Necropsy revealed blood in the thoracic and perit...
Boy MG, Palmer JE, Heyer G, Hamir AN.Gastric leiomyosarcoma was diagnosed in a 12-year-old Thoroughbred gelding. The horse was examined because of anorexia, weight loss, and intermittent fever of 1.5 months' duration. Antemortem diagnostic testing was extensive, but a definitive diagnosis could not be reached with noninvasive methods. Exploratory celiotomy confirmed an intra-abdominal mass, and the horse was euthanatized. Necropsy revealed a firm mass associated with the distal portion of the esophagus, cranial two thirds of the stomach, and visceral surface of the liver. The histopathologic diagnosis was leiomyosarcoma.
MacGillivray KC, Graham TD, Parente EJ.A 2-year-old male Thoroughbred was evaluated for multiple firm, raised nodules of the maxilla and mandible that had been present since 6 months of age. The horse was evaluated as a yearling with a final histologic diagnosis of fibrosarcoma. As a 2-year-old, the colt made a loud upper airway sound and was agitated after strenuous exercise. Results of upper airway endoscopy indicated severe narrowing of the nasal passages and pharynx with normal resting function. Radiography revealed multiple circular bony lesions in the mandible, maxilla, multiple long bones, and cervical vertebrae. Biopsy spec...
Cesar FB, Joiner KS, Albanese V, Groover ES, Waguespack RW.This research article discusses a case of a one-year-old Quarter Horse colt diagnosed with a rare condition known as osteoblastic osteosarcoma in the left paranasal sinuses. Despite treatment attempts, the […]