Tumors in horses are abnormal growths of tissue that result from uncontrolled cell division. They can be benign or malignant and may affect various tissues and organs within the equine body. Common types of tumors in horses include sarcoids, melanomas, and squamous cell carcinomas. The presence and progression of tumors can impact a horse's health, performance, and quality of life. Diagnosis often involves clinical examination, imaging techniques, and histopathological analysis. This page compiles peer-reviewed research studies and scholarly articles that explore the types, diagnosis, treatment options, and prognostic factors associated with tumors in equine medicine.
Gysens L, Depuydt E, Patruno M, Haspeslagh M, Spaas JH, Martens A.Sarcoids are the most common equine skin tumours Although they do not metastasize, they can be locally aggressive and cause significant clinical symptoms in affected horses. Despite being common, very little is known about the host immune response and the biological mechanisms underlying persistence and recurrence of equine sarcoids. The latter reflects the need for further research in this field. This in-vitro study used sarcoid explants from horses with naturally occurring sarcoids (n = 12) to evaluate the induction of a humoral immune response directed against equine sarcoid-derived bovin...
Drozdzewska K, Gehlen H.The diagnosis of internal neoplasia in horses is challenging. Increased production of hormones physiologic for adult animals (e.g., adrenocorticotropin, norepinephrine, and erythropoietin) or typical for the foetal phase (alpha-fetoprotein, anti-Müllerian hormone, and parathyroid-hormone-related protein) might aid in tumour diagnostics. Thymidine kinase-1 and alkaline phosphatase are examples of intracellular enzymes, whose activity in the blood may increase in some neoplasia cases. Furthermore, inappropriate production of abnormal monoclonal or autologous antibodies can accompany lymphoma an...
Daraban Bocaneti F, Altamura G, Corteggio A, Tanase OI, Dascalu MA, Pasca SA, Hritcu O, Mares M, Borzacchiello G.Bovine papillomaviruses -1/-2 (BPVs) are small non-enveloped double-stranded DNA viruses able to infect the skin of bovids and equids, causing development of neoplastic lesions such as bovine cutaneous fibropapillomas and equine sarcoid. Matrix metalloproteinases (MMPs) are a group of zinc-dependent endopeptidases that degrade basal membrane and extracellular matrix, whose function is essential in physiological processes such as tissue remodeling and wound healing. MMPs activity is finely regulated by a balancing with expression of tissue inhibitors of MMPs (TIMPs), a process that is impaired ...
Nakayama H, Shiga T, Uchida K, Chambers JK, Morino T, Sasaki N.There is no nationwide necropsy database of animals in Japan, and most of the records are available from the postwar period. To clarify the chronological transition of animal necropsy cases in Tokyo, Japan, the records accumulated in The University of Tokyo from 1902 were investigated. Of necropsy records on paper or electronic from 1902 to 2021 kept at the Laboratory of Veterinary Pathology, The University of Tokyo, totally 3,137 cases including 572 in 1903-1914 (the Meiji-Taisho period), 1,258 in 1956-1969 (the Showa period) and 1,307 in 2006-2020 (the Heisei-Reiwa period), respectively, wer...
Wotman KL, Chow L, Martabano B, Pezzanite LM, Dow S.Ocular surface squamous neoplasia (OSSN) is the major cause of corneal cancer in man and horses worldwide, and the prevalence of OSSN is increasing due to greater UVB exposure globally. Currently, there are no approved treatments for OSSN in either species, and most patients are managed with surgical excision or off-label treatment with locally injected interferon alpha, or topically applied cytotoxic drugs such as mitomycin C. A more broadly effective and readily applied immunotherapy could exert a significant impact on management of OSSN worldwide. We therefore evaluated the effectiveness of...
Stefanik E, Górski K, Turek B, Drewnowska-Szczepakowska O, Kliczkowska-Klarowicz K, Stefanik A.Melanomas in horses are most often associated with gray, older horses with an average age of over 16 years. Anaplastic malignant melanoma, however, can very rarely affect non-gray horses. Herein, we report a case of a 16-year-old Wielkopolski gelding with a chronic lameness caused by a mass in the hoof. The first resection of the lesion and histopathological examination confirmed the presence of a keratoma. The regrown mass and persistent lameness resulted in another mass resection. The second histopathological examination result suggested a neoplastic growth of melanocytic origin with a low h...
Yi Z, Gao Y, Yu F, Zhu Y, Liu H, Li J, Murua Escobar H.Several therapies have been developed to treat equine cutaneous melanoma, but formal comparisons among different treatment options are currently unavailable. It was our intent to assess the efficacy of different treatment protocols and the quality of the studies based on the original published data, and summarize the knowledge concerning the outcome after equine cutaneous melanoma management. This structured review followed PRISMA procedure to search for treatment protocols on equine cutaneous melanoma published from 1960 until June 2021. Studies were assessed for the risk of bias. A descripti...
Gysens L, Martens A, Haspeslagh M.Although bovine papillomavirus (BPV)-induced equine sarcoids are often identified solely by clinical examination, confirmation of the clinical diagnosis is essential for correct treatment selection. Only few approaches are presently available for this purpose. PCR-based screening for BPV in superficial swabs is widely-used to support clinical suspicion. While this method effectively detects sarcoid involvement in ulcerated lesions, sensitivity is lower in tumors with intact epithelium. This cross-sectional study compared the diagnostic characteristics of superficial swabs and fine-needle aspir...
Nelissen S, Miller AD.Granulosa cell tumors (GCTs) are common ovarian neoplasms in the mare and bitch that can be challenging to diagnose on histopathology. Inhibin has long been the standard immunohistochemical (IHC) marker for GCTs; however, anti-Müllerian hormone (AMH) has not been evaluated widely as an IHC marker in the bitch and mare. We compared the efficacy of AMH and inhibin as IHC markers in canine and equine GCTs. We selected retrospectively 18 equine and 15 canine cases. All equine tumors were dominated by a cystic pattern; canine tumors often had solid patterns. Both inhibin and AMH had similar puncta...
Tura G, Brunetti B, Brigandì E, Rinnovati R, Sarli G, Avallone G, Muscatello LV, La Ragione RM, Durham AE, Bacci B.Sarcoids are among the most common tumors diagnosed in equids; their association with bovine papillomaviruses (BPV) infection has been widely reported, but the mechanism of carcinogenesis has not been fully elucidated. To verify whether BPV infection causes dysregulation of the pRb-Cyclin D1-p16-p53 pathway as reported for human papillomavirus (HPV), the study employed immunohistochemistry to test 55 equine sarcoid biopsies for the expression of pRb, Cyclin D1, and p53 cell cycle regulatory proteins and to evaluate the proliferative rate through Ki67. High Cyclin D1 and pRb expression were obs...
Ciaputa R, Gach J, Baranowski K, Dzimira S, Janus I, Kandefer-Gola M, Żebrowski K, Nowak M.An analysis of samples originating from domestic and exotic animals from Lower Silesia but also from other parts of Poland was carried out based on research conducted in 2014-2017. Unassigned: The materials used for the study were 11,338 tumour samples taken in vivo during surgery and as biopsies and posthumously during necropsies. They were sent to the Department of Pathology at Wrocław University of Environmental and Life Sciences for histopathological diagnosis. Unassigned: The largest group were canine tumours, of which there were 9,745 (85.95%), followed by feline tumours, totalling 1,39...
Romero BF, Iglesis García M, Gil Molino M, Gómez L, Galapero J, Parejo C, Martín Cuervo M.Equine uveitis is a common eye disease that affect horses from different breeds, ages, and genders. Uveitis has been described as inflammation of the uvea secondary immunomediated processes or eye trauma. Renal cell carcinoma (RCC) is the most common tumor that can affect the equine kidneys. The present case describe a horse that was referred to the Veterinary Teaching Hospital of the University of Extremadura with bilateral uveitis. The horse was treated for the primary complain but the horse collapse and die during hospitalization. At necropsy, a tumoral mass in kidney with extensive in othe...
Beatriz FR, Marta VG, María MC, Joaquín JF, Esther DF, Luis-Javier EC, Gabriel MD, Manuel IG.An 8-year-old mare mule was presented with a facial mass and history of anorexia, unilateral epistaxis and purulent nasal discharge. The facial mass was encountered from the ventral to the lateral right canthus of the eye up to the facial crest. Thoracic ultrasonography showed five rounded masses. A standing CT under sedation was performed revealing a huge extension and infiltration on surrounding tissues. Due to the extension, type of lesions, outcome and suspicion of metastasis, the owner chose to euthanize the patient. Necropsy confirmed the presence of tumoral lesions spread into the lungs...
Huang L, Palmieri C, Bertin FR.Pituitary pars intermedia dysfunction (PPID) is an endocrinopathy commonly affecting old horses. It is a spontaneously occurring, progressive disease that is still poorly understood. Previous studies have observed neurodegeneration of the dopaminergic inhibition of melanotrophs, which leads to decreased dopamine (DA) in the pars intermedia (PI) and increased pro-opiomelanocortin-derived peptides circulating in plasma. However, rats knockout for the dopamine D2 receptor (D2r) similarly develop PI hypertrophy and hyperplasia. Thus, based on the current pathophysiological theory of PPID, whether ...
Ochi A, Nishioka T, Kurimoto S, Kishi D, Ueno T, Nukada T.A 2-year-old male Thoroughbred horse presented with a mass in the maxilla. The focally ulcerated mass, approximately 8 cm in diameter, covered the upper left intermediate and corner incisor teeth (nos. 602 and 603 according to the modified Triadan system) and radiographic examination revealed displacement and lysis of the incisors. Histologically, the tumour was composed of a dense proliferation of spindle-shaped cells and neoplastic odontogenic epithelial cells arranged in island, follicular, plexiform or sheetlike patterns. The spindle-shaped cells were immunopositive for cytokeratins AE1/A...
Witkowski M, Duliban M, Rak A, Profaska-Szymik M, Gurgul A, Arent ZJ, Galuszka A, Kotula-Balak M.Endometrosis is a periglandular fibrosis associated with dysfunction of affected glandular epithelial cells that is the most common cause of reduced fertility in mares, although it is not fully understood. The etiology of the disease is still partially unknown. This study focuses on understanding the genetic mechanisms potentially underlying endometrosis in mares using the Next Generation Sequencing (NGS) technique. Endometrial samples, used in the study, were obtained in the anestrus phase both from healthy mares and those diagnosed with endometrosis. The NGS data were analyzed for gene invol...
Podstawski P, Ropka-Molik K, Semik-Gurgul E, Samiec M, Skrzyszowska M, Podstawski Z, Szmatoła T, Witkowski M, Pawlina-Tyszko K.An important component of tissues is the extracellular matrix (ECM), which not only forms a tissue scaffold, but also provides the environment for numerous biochemical reactions. Its composition is strictly regulated, and any irregularities can result in the development of many diseases, including cancer. Sarcoid is the most common skin cancer in equids. Its formation results from the presence of the genetic material of the bovine papillomavirus (BPV). In addition, it is assumed that sarcoid-dependent oncogenic transformation arises from a disturbed wound healing process, which may be due to t...
Saba C, Eggleston R, Parks A, Peroni J, Sjoberg E, Rice S, Tyma J, Williams J, Grosenbaugh D, Leard AT.Sarcoid tumors are common in horses and may negatively impact the performance and value of the horse. No known treatment is reliably successful. Objective: To determine tolerability, overall response rate, time to response, and progression-free survival of horses with biopsy-confirmed or suspected sarcoids treated with ALVAC-fIL2. Methods: Client-owned horses with measurable, presumed- or biopsy-confirmed sarcoid tumors. Methods: Prospective pilot study. One milliliter of ALVAC-fIL2 was injected into 4 to 5 areas of the sarcoid(s) in each horse (week 0); this treatment was repeated in weeks 1,...
Greenberg CB, Javsicas LH, Clauson RM, Suckow MA, Kalinauskas AE, Lucroy MD.Autologous cancer vaccines (ACV) are an emerging option for adjuvant cancer treatment in veterinary medicine. With this form of active immunotherapy, the patient's tumor cells are processed ex vivo and returned to the patient with the goal of stimulating an immune response to unique, patient-specific antigens. The case accession database at Torigen was queried to identify horses that underwent biopsy or surgical resection of their primary tumor and received at least one subcutaneous dose of an adjuvanted whole-cell autologous cancer vaccine. The records were then reviewed for any reported adve...
Podstawski P, Ropka-Molik K, Semik-Gurgul E, Samiec M, Skrzyszowska M, Podstawski Z, Szmatoła T, Witkowski M, Pawlina-Tyszko K.Matrix metalloproteinases (s) represent a family of enzymes capable of biocatalytically breaking down the structural and functional proteins responsible for extracellular matrix (ECM) integrity. This capability is widely used in physiological processes; however, imbalanced MMP activity can trigger the onset and progression of various pathological changes, including the neoplasmic transformation of different cell types. We sought to uncover molecular mechanisms underlying alterations in transcriptional profiles of genes coding for s, which were comprehensively identified in equine adult dermal ...
Tesena P, Kingkaw A, Phaonakrop N, Roytrakul S, Limudomporn P, Vongsangnak W, Kovitvadhi A.Equine melanocytic neoplasm (EMN) is a common disease in older grey horses. The purpose of this study was to examine the potential proteins throughout EMN stages from faecal proteomic outlining using functional analysis. Faecal samples were collected from the rectum of 25 grey horses divided into three groups; normal group without EMN ( = 10), mild EMN ( = 6) and severe EMN ( = 9). Based on the results, 5910 annotated proteins out of 8509 total proteins were assessed from proteomic profiling. We observed differentially expressed proteins (DEPs) between the normal group and the EMN group, and 1...
Strohmayer C, Klang A, Kummer S, Walter I, Jindra C, Weissenbacher-Lang C, Redmer T, Kneissl S, Brandt S.Squamous cell carcinoma of the head and neck (HNSCC) is a common malignant tumor in humans and animals. In humans, papillomavirus (PV)-induced HNSCCs have a better prognosis than papillomavirus-unrelated HNSCCs. The ability of tumor cells to switch from epithelial to mesenchymal, endothelial, or therapy-resistant stem-cell-like phenotypes promotes disease progression and metastasis. In equine HNSCC, PV-association and tumor cell phenotype switching are poorly understood. We screened 49 equine HNSCCs for equine PV (EcPV) type 2, 3 and 5 infection. Subsequently, PV-positive versus -negative lesi...
Podstawski P, Samiec M, Skrzyszowska M, Szmatoła T, Semik-Gurgul E, Ropka-Molik K.The equine sarcoid is one of the most common neoplasias in the family. Despite the association of this tumor with the presence of bovine papillomavirus (BPV), the molecular mechanism of this lesion has not been fully understood. The transgenization of equine adult cutaneous fibroblast cells (ACFCs) was accomplished by nucleofection, followed by detection of molecular modifications using high-throughput NGS transcriptome sequencing. The results of the present study confirm that - and -mediated nucleofection strategy significantly affected the transcriptomic alterations, leading to sarcoid-like...
Schreeg ME, Radkin M, Haugland J, Murphy BG, Rushton S, Linder KE.Ameloblastic carcinoma is a malignant odontogenic neoplasm that has been reported only rarely in veterinary species. A 16-y-old Arabian crossbred mare was presented for evaluation of a hard mass on the body of the mandible, with evidence of osteolysis on radiographs. Incisional biopsies revealed an invasive neoplasm comprised of spindloid epithelial cells with a high mitotic count and partial dual cytokeratin-vimentin immunoreactivity. The horse was euthanized because of rapid tumor progression 3 mo after presentation. Postmortem evaluation revealed partial obliteration of the mandible by a ...
Martano M, Altamura G, Power K, Liguori P, Restucci B, Borzacchiello G, Maiolino P.It is well known that δ-bovine papillomaviruses (BPV-1, BPV-2 and BPV-13) are one of the major causative agents of equine sarcoids, the most common equine skin tumors. Different viruses, including papillomaviruses, evolved ingenious strategies to modulate autophagy, a complex process involved in degradation and recycling of old and damaged material. Methods: The aim of this study was to evaluate, by immunohistochemistry (IHC) and Western blot (WB) analysis, the expression of the main related autophagy proteins (Beclin 1, protein light chain 3 (LC3) and P62), in 35 BPV1/2 positive equine sarco...
Cosandey J, Hamza E, Gerber V, Ramseyer A, Leeb T, Jagannathan V, Blaszczyk K, Unger L.MicroRNAs have been proposed as biomarkers for equine sarcoids, the most prevalent equine skin tumors globally. This study served to validate the diagnostic and prognostic potential of whole blood microRNAs identified in a previous study for long-term equine sarcoid diagnosis and outcome prediction. Based on findings of a clinical examination at the age of 3 years and a follow-up following a further 5-12 years, 32 Franches-Montagnes and 45 Swiss Warmblood horses were assigned to four groups: horses with regression (n = 19), progression (n = 9), new occurrences of sarcoid lesions (n = 19) and t...
Zetterström SM, Matz BM, Neto RLALT, Lindley SES, Cole RC, Wilhite R, Boone LH.To describe the surgical findings, histopathological features, and long-term outcome for a horse with parotid salivary carcinoma. Methods: Case report ANIMALS: Twelve year old American Quarter Horse gelding. Methods: The gelding was presented for a 10 × 10 cm swelling below the base of the right ear. Ultrasonographic examination revealed a mass involving the right parotid salivary gland. Incisional biopsy was consistent with parotid carcinoma. The tumor was marginally excised. The lateral wall of the guttural pouch was excised with the mass and was reconstructed with a porcine small int...
Jindra C, Hainisch EK, Rümmele A, Wolschek M, Muster T, Brandt S.Bovine papillomaviruses types 1 and 2 (BPV1, BPV2) commonly induce skin tumours termed sarcoids in horses and other equids. Sarcoids seriously compromise the health and welfare of affected individuals due to their propensity to resist treatment and reoccur in a more severe form. We have developed influenza (Flu) A and B virus vectors that harbour a truncated NS1 gene (iNS) assuring interferon induction and co-express shuffled BPV1 E6 and E7 antigens for sarcoid immunotherapy. In a safety trial involving 12 healthy horses, intradermal administration of iNSA/E6E7equ and iNSB/E6E7equ was well tol...
Weber LA, Delarocque J, Feige K, Kietzmann M, Kalbitz J, Meißner J, Paschke R, Cavalleri JV.The naturally occurring betulinic acid (BA) and its derivative NVX-207 induce apoptosis in equine melanoma cells in vitro. After topical application, high concentrations of the substances can be reached in healthy equine skin. With the aim to investigate the effect and safety of topically applied BA and NVX-207 in horses with melanocytic tumors, the longitudinal, prospective, randomized, double-blind, placebo-controlled study protocol included eighteen Lipizzaner mares with early-stage cutaneous melanoma assigned to three groups. Melanocytic lesions were topically treated either with a placebo...
Druml T, Brem G, Velie B, Lindgren G, Horna M, Ricard A, Grilz-Seger G.In horses, the autoimmune disease vitiligo is characterized by the loss of melanocytes and results in patchy depigmentation of the skin around the eyes, muzzle and the perianal region. Vitiligo-like depigmentation occurs predominantly in horses displaying the grey coat colour and is observed at a prevalence level of 26.0-67.0% in grey horses compared with only 0.8-3.5% in non-grey horses. While the polygenetic background of this complex disease is well documented in humans, the underlying candidate genes for this skin disorder in horses remain unknown. In this study we aim to perform a genome-...
Campagne C, Julé S, Bernex F, Estrada M, Aubin-Houzelstein G, Panthier JJ, Egidy G.Melanocytic proliferations are common in horses but the diagnosis of malignancy is not always straightforward. To improve diagnosis and prognosis, markers of malignancy are needed. Receptor for activated C kinase 1 (RACK1) protein may be such a marker. RACK1 was originally found to characterize malignant melanocytic lesions in the Melanoblastoma-bearing Libechov minipig (MeLiM) and, later, in human patients. Our purpose was to investigate the value of RACK1 in the classification of cutaneous melanocytic proliferations in horses. Results: Using immunofluorescence, we report here that both MITF ...
Pimenta J, Prada J, Cotovio M.Adult grey horses have a high incidence of melanocytic tumors. This article narratively reviews the role of some genetic features related to melanoma formation in horses, such as STX17 mutation, ASIP or MITF alterations, and the link between the graying process and the development of these tumors. A clear system of clinical and pathological classification of melanocytic tumors in naevus, dermal melanoma, dermal melanomatosis and anaplastic malignant melanoma is provided. Clinical and laboratorial methods of diagnosing are listed, with fine needle aspiration and histopathology being the most re...
Hartl B, Hainisch EK, Shafti-Keramat S, Kirnbauer R, Corteggio A, Borzacchiello G, Tober R, Kainzbauer C, Pratscher B, Brandt S.Bovine papillomavirus types 1 and 2 (BPV-1 and BPV-2) are known to induce common equine skin tumours, termed sarcoids. Recently, it was demonstrated that vaccination with BPV-1 virus-like particles (VLPs) is safe and highly immunogenic in horses. To establish a BPV-1 challenge model for evaluation of the protective potential of BPV-1 VLPs, four foals were injected intradermally with infectious BPV-1 virions and with viral genome-based and control inocula, and monitored daily for tumour development. Blood was taken before inoculation and at weekly intervals. BPV-1-specific serum antibodies were...
Yuan Z, Gault EA, Campo MS, Nasir L.Equine sarcoids represent the most common skin tumours in equids worldwide, characterized by localized invasion, rare regression and high recurrence following surgical intervention. Bovine papillomavirus type 1 (BPV-1) and less commonly BPV-2 are now widely recognized as the causative agents of the disease. Fibroblasts isolated from sarcoids are highly invasive. Invasion is associated with a high level of viral gene expression and matrix metalloproteinase upregulation. However, it remains unclear to what extent BPV-1 proteins are involved in the transformation of equine cells. To address this ...
Armando F, Mecocci S, Orlandi V, Porcellato I, Cappelli K, Mechelli L, Brachelente C, Pepe M, Gialletti R, Ghelardi A, Passeri B, Razzuoli E.Equine penile squamous cell carcinoma (epSCC) is the most frequent tumor of the external male genitalia, representing 67.5% of equine genital cancers. epSCC is associated with papilloma virus (PV) infection and has been recently proposed as a model for human PV-induced squamous cell carcinomas. It has already been suggested that epSCC might undergo epithelial-to-mesenchymal transition (EMT). This work aims to investigate in detail this process and the possible role of PV oncoproteins in epSCC. For this purpose, 18 penile SCCs were retrospectively selected and tested for both EcPV2 presence and...
Yuan Z, Gallagher A, Gault EA, Campo MS, Nasir L.Bovine papillomavirus (BPV) type 2 is involved in carcinogenesis of the urinary bladder in cattle, while BPV-1 is commonly associated with equine sarcoid tumours. In both cases the early viral proteins are expressed, but virion is not produced. Given the similarities in BPV biology between the tumours in cattle and horses, bovine bladder cancers and equine sarcoids were compared with respect to physical status, load of viral DNA and variability of the E5 open reading frame (ORF). Rolling circle amplification demonstrated that BPV-1 and BPV-2 genomes exist as double stranded, episomal, circular...
Lazary S, Gerber H, Glatt PA, Straub R.The distribution of equine leucocyte antigens (ELA) in horses affected by equine sarcoid tumours was determined and compared with unaffected controls. ELA-haplotype W3,B1 occurred more frequently in affected riding horses of Irish, Swiss and French background. The combined data for the three breeds resulted in a chi 2 value of 20.35 (P less than 0.0005 after correction). Simultaneously, ELA-specificity W11 was more frequently found in horses of Irish background, while W5 was found in Swiss and French horses with sarcoids. The combined data for haplotype W3,B1 and/or W5 specificity demonstrated...
Martineau D, Bowser PR, Wooster G, Forney JL.Sixty-seven adult walleye fish were examined by light and transmission electron microscopy. The fish were affected by a mesenchymal tumor previously termed Walleye Dermal Sarcoma that commonly affects up to 27% of the population seasonally. Biopsies from 24 fish were collected, and complete postmortem examinations were performed on 43 fish. Grossly, the tumors had the appearance of randomly distributed, often clustered, spherical nodules, 2-5 mm in diameter with a smooth and often ulcerated surface. The tumors arose from the superficial surface of scales and consisted of fibroblast-like cells ...
Martens A, De Moor A, Demeulemeester J, Peelman L.To examine apparently normal skin around equine sarcoids for evidence of bovine papilloma virus (BPV) DNA, and to relate this finding to the observed recurrence after surgery. Methods: Prospective study. Methods: Forty-one equine sarcoids from 19 horses. Methods: The tumors were surgically excised at a measured distance of 8, 12, or 16 mm. Samples from the tumor and of the entire surrounding skin were taken at 4, 8, 12, and 16 mm from the tumor border and analyzed for the presence of BPV DNA using polymerase chain reaction (PCR) amplification. The samples were grouped per examined sarcoid, and...
Kelley LC, Mahaffey EA.Gross lesions, microscopic appearance, and immunophenotyping are reported in a retrospective study of 31 cases of equine malignant lymphoma. Immunohistochemical studies were performed on archived formalin-fixed, paraffin-embedded tissues. Monoclonal antibodies to surface glycoprotein BLA.36 and intracytoplasmic domains of mb-1 and B29 were used to document the presence of B lymphocytes in the equine tumors. Polyclonal antibody to CD3 and monoclonal antibodies to T-lymphocyte markers CD3 and CD5 revealed the presence of variable numbers of T cells within the equine lymphomas. The neoplastic com...
Théon AP, Pascoe JR, Carlson GP, Krag DN.Twenty horses with 30 lesions were studied to evaluate the effects of intratumoral chemotherapy with cisplatin in sesame oil on equine sarcoids (n = 19), squamous cell carcinomas (n = 7), and squamous cell papillomas (n = 4). Treatment consisted of 4 sessions of intratumoral cisplatin chemotherapy at 2-week intervals. A controlled-release formulation of cisplatin in sesame oil was used to limit drug egress from the injection site. Mean dosage per session was 0.97 (+/- 0.17, SEM) mg of cisplatin/cm3 of tumor tissue treated for tumor volumes ranging from 10 to 20 cm3. Dosage tended to be slightl...
Broström H.Associations between clinical parameters of sarcoids and the equine leucocyte antigen system (ELA) were analysed for 120 Swedish horses. Median age of affected horses was 5.2 years, and the majority presented with solitary tumors between 2 and 5 cm in diameter and ventral abdomen was a predilection site. Clinical signs first appeared at a median age of 3.5 years, and sarcoids at different locations first appeared at different ages. Lesions at different sites differed in size, and multiple tumors, early onset, long duration, and older age all had an association with large size. Clinical manifes...
Cissell DD, Wisner ER, Textor J, Mohr FC, Scrivani PV, Théon AP.The computed tomography (CT) features of tumors involving the nasal cavity and/or paranasal sinuses of 15 horses were reviewed. The 15 tumors included five neuroendocrine tumors/neuroblastomas, two undifferentiated carcinomas, two myxosarcomas, and one each of nasal adenocarcinoma, hemangiosarcoma, chondroblastic osteosarcoma, anaplastic sarcoma, myxoma, and ossifying fibroma. All tumors except the ossifying fibroma were iso- or hypoattenuating relative to masseter muscle. Thirteen of the fifteen tumors exhibited moderate or marked osteolysis of adjacent cortical bone and 14/15 were characteri...
Fleury C, Bérard F, Leblond A, Faure C, Ganem N, Thomas L.An epidemiological survey was made on cutaneous melanomas occurring in Camargue-type, gray-skinned horses in southern France. The population investigated was composed of 264 horses, which were selected from the Camargue horse stud registry and were allowed to be examined by the owners. The presence of tumors was inspected macroscopically according to the standardized protocols of veterinary medicine specialists, and some tumors were subjected to macroscopic histopathological examination. The results indicated that: 1) the prevalence of melanomas in the overall population was 31.4%; 2) the odds...
Morse CC, Saik JE, Richardson DW, Fetter AW.Benign proliferative fibro-osseous lesions of the rostral mandible in six young horses are classified as equine juvenile mandibular ossifying fibroma. Histologically there is a characteristic abrupt transition from subgingival fibroblastic stroma to a zone of proliferating osteoblasts that form irregular spicules of osteoid. The layer of proliferating osteoblasts blends with a deeper zone of bony trabeculae rimmed by osteoblasts and separated by intertrabecular spaces of moderate cellular density. Incomplete surgical excision resulted in local recurrence, while rostral mandibulectomies resulte...
Schöniger S, Valentine BA, Fernandez CJ, Summers BA.Schwannomas are uncommonly recognized in horses. This study describes cutaneous schwannomas in 22 horses aged 8 to 25 years: 12 male, 7 female, and 3 of unknown sex. The horses had solitary cutaneous masses: 9 on the head, 3 on the neck, and the others on the shoulder, hip, thorax, abdomen, rump, extremities, or tail. The location of 1 tumor was unknown. The dermal tumors were well demarcated and expansile. Twelve had a multinodular pattern, whereas 10 formed a single nodule. Antoni A areas were observed in all tumors, and 10 tumors contained Antoni B areas. In Antoni A areas, the densely pack...
King TC, Priehs DR, Gum GG, Miller TR.The records of 50 horses with ocular squamous cell carcinoma (OSCC) presented to the University of Florida Veterinary Medical Teaching Hospital over an 11 year period were reviewed to determine the influence of therapy on the outcome of the case. Follow-up information was obtained for 43 of the 50 cases. The disease was more prevalent in the light horse breeds; however, the draft breeds also were at risk. There was no sex predisposition and the average age was 11.8 years. Tumour recurrence was significant when surgery alone was performed. The eyelid and nictitating membrane were the primary si...
Argyle D, Ellsmore V, Gault EA, Munro AF, Nasir L.To determine the role of telomeres in cellular ageing in equids, we analysed telomere lengths in peripheral blood derived DNA samples from a panel of donkeys (Equus asinus) ranging from 2 to 30 years of age. The average telomere lengths ranged from 7 to 21 kbp and a statistically significant inverse correlation between telomere lengths and donor age was demonstrated. Similarly, telomere lengths in primary fibroblasts isolated from a horse (Equus equus) demonstrated telomeric loss with in vitro ageing when cultured to senescence. We extended this study to evaluate activity of the enzyme telomer...
McCue PM, Roser JF, Munro CJ, Liu IK, Lasley BL.The granulosa cell tumor is the most common ovarian tumor in mares. A clinical diagnosis can be made based on the presence ofa unilaterally enlarged ovary and a small inactive contralateral ovary. Endocrine testing may be beneficial to confirm a diagnosis. Surgical removal of the tumor eliminates the adverse effect on pituitary function and results in resumption of follicular development and ovulation in the opposite ovary over time.
Pascoe RR, Summers PM.The results of a retrospective survey of tumours and tumour-like lesions encountered in horses in a veterinary practice in south east Queensland between 1956 and 1978 are presented. Forty-two per cent of the lesions were examined histologically. The most commonly occurring neoplasms were the equine sarcoid, papilloma and squamous cell carcinoma of the eye and external genitalia. Neurofibroma was an important problem in the eyelid region. Intra-abdominal tumours were rarely encountered in this series.
Wilson AD, Armstrong ELR, Gofton RG, Mason J, De Toit N, Day MJ.Sarcoids are common skin tumours of horses and donkeys that are characterised by persistent proliferation of dermal fibroblasts associated with the presence of bovine papillomavirus (BPV) DNA. Some early BPV proteins have been demonstrated within sarcoids and RNA containing both early and late transcripts is present, yet it remains unclear whether late replication of BPV, culminating in the production of infectious virus particles, can occur in equids. Here we report that BPV1 RNA isolated from equine sarcoids encodes a unique deletion of four residues within the L2 protein suggesting a novel ...
Yuan Z, Gobeil PA, Campo MS, Nasir L.Papillomaviruses are DNA viruses that cause tumours of the skin in humans and animals. The natural host of bovine papillomavirus is cattle, but also equids, resulting in tumours termed sarcoids. Matrix metalloproteinase 1 (MMP-1) expression is up-regulated in sarcoid fibroblasts and tumours. We extended our observation to other MMPs and determined whether MMPs induced invasion of sarcoid fibroblasts. Collagenase (MMP-1) and Gelatinase (MMP-2, MMP-9) were over-expressed in sarcoid fibroblasts and tumours. The fibroblasts were invasive in a 3D/matrigel invasion assay system. Inhibition of MMP by...
Goodrich L, Gerber H, Marti E, Antczak DF.Sarcoids, the most common tumor of the horse, are fibroblastic, wart-like skin lesions that show variable manifestations. They are often invasive and recurrent, although they do not fulfill all criteria of malignancy. Due to their anatomic location, these tumors can sometimes cause loss of use of the horse. There is very strong evidence that sarcoids are caused by viruses closely related or identical to bovine papilloma viruses, and genetic studies have shown associations between genes in or near the equine major histocompatibility complex (MHC) and susceptibility to sarcoid. Several types of ...
Finlay M, Yuan Z, Morgan IM, Campo MS, Nasir L.Bovine papillomavirus type 1 infects not only cattle but also equids and is a causative factor in the pathogenesis of commonly occurring equine sarcoid tumours. Whilst treatment of sarcoids is notoriously difficult, cisplatin has been shown to be one of the most effective treatment strategies for sarcoids. In this study we show that in equine fibroblasts, BPV-1 sensitises cells to cisplatin-induced and UVB-induced apoptosis, a known cofactor for papillomavirus associated disease, however BPV-1 transformed fibroblasts show increased clonogenic survival, which may potentially limit the therapeut...
Lancaster WD, Theilen GH, Olson C.DNAs from bovine papilloma virus(BPV)-induced hamster tumors and from equine connective tissue tumors of unknown etiology were examined for BPV DNA sequences by molecular hybridization. DNA from two distinct classes of BPV (type 1 and type 2) was labeled in vitro and used as probes. Analysis of DNA-DNA reassociation kinetics indicated that both virus types were capable of tumor induction in the hamster. DNA isolated from 6 of 7 equine tumors accelerated the reassociation of the BPV DNA probes. BPV type 1 or type 2 DNA hybridized extensively to DNA from 3 tumors, while 3 other tumors contained ...
This mini-review presents the results of veterinary clinical trials on immunogene therapy published from 2014 to 2016. A variety of tumors, among them melanoma (canine and equine), mastocytoma (canine), mammary adenocarcinoma (canine) and fibrosarcoma (feline) were treated by using diverse strategies. Non-viral vectors were usually employed to transfer genes of cytokines, suicide enzymes and/or tumor associated antigens. In general terms, minor or no adverse collateral effects were related to these procedures, and treated patients frequently improved their conditions (better quality of life, d...
Spoormakers TJ, Klein WR, Jacobs JJ, Van Den Ingh TS, Koten JW, Den Otter W.Local interleukin-2 (IL-2) is effective in a number of experimental animal models and in veterinary and human cancer patients without discomforting side effects. The primary goal of this study was to compare the therapeutic effects and side effects of the local intratumoral administration of five or ten low doses of IL-2 with those of a combination of cisplatin and a single high dose of IL-2 in the treatment of equine sarcoids. The therapeutic effect (complete and partial regression) of local cisplatin together with a single high dose of IL-2 was significantly better than the combined effect o...
Ramos-Vara JA, Frank CB, DuSold D, Miller MA.The immunoreactivity of PNL2, Melan A, and protein gene product (PGP) 9.5 was compared with that of S100 protein in 50 formalin-fixed, paraffin-embedded equine melanocytic neoplasms. PNL2, PGP 9.5, and S100 protein were detected in all 50 neoplasms; none expressed Melan A. PNL2 was not expressed in 62 nonmelanocytic tumors (equine sarcoids, schwannomas, carcinomas, sarcomas, endocrine tumors, sex-cord stromal tumors, germ cell tumors, and leukocytic tumors) or in normal tissues other than epidermis. In summary, antibody PNL2 is a sensitive marker of equine melanocytic neoplasms and is more spe...
Lichtenstein F, Iqbal A, de Lima Will SEA, Bosch RV, DeOcesano-Pereira C, Goldfeder MB, Chammas R, Trufen CEM, Morais KLP, de Souza JG, Natalino RJM....We have investigated Amblyomin-X-treated horse melanomas to better understand its mode of action through transcriptome analysis and the in vivo model. Amblyomin-X is a Kunitz-type homologous protein that selectively leads to the death of tumor cells via ER stress and apoptosis, currently under investigation as a new drug candidate for cancer treatment. Melanomas are immunogenic tumors, and a better understanding of the immune responses is warranted. Equine melanomas are spontaneous and not so aggressive as human melanomas are, as this study shows that the in vivo treatment of encapsulated hors...
