Topic:Malignancy
Malignancy in horses refers to the presence and study of cancerous cells and tumors within equine species. This topic encompasses the identification, characterization, and treatment of various types of cancers affecting horses. Common malignancies in horses include squamous cell carcinoma, melanoma, and lymphosarcoma. These conditions can impact different tissues and organs, leading to a range of clinical presentations. Research in this area focuses on understanding the pathophysiology of equine cancers, diagnostic methods, and therapeutic interventions. This page aggregates peer-reviewed research studies and scholarly articles that explore the epidemiology, molecular biology, and clinical management of malignancies in horses.
The Impact of Excision Interval on Equine Melanoma Progression: Time Matters? Equine melanomas are a common neoplasm in gray horses. However, scientific knowledge about their progression over time is quite scarce. Some owners and veterinarians still believe that early intervention is not necessary, stating that tumors evolve very slowly and intervention could worsen the animal's condition. This work aims to identify clinical and histological differences that may exist between equine melanomas with different excision intervals (time between tumor detection and surgical excision). A total of 42 tumors (13 benign and 29 malignant) from 34 horses were included in this study...
The oncogenic pathways of papillomaviruses. Papillomaviruses are oncogenic DNA viruses and induce hyperplastic benign lesions of both cutaneous and mucosal tissues in their various hosts, including many domestic and wild animals as well as humans. There are some Papillomavirus genotypes that can infect hosts different from their own, such as BPV 1 and BPV 2 originated from cattle, which can also infect horses and are responsible for fibroblastic tumours in horses. This review article summarizes the origin and evolution of papillomaviruses as an etiological agent in the historical process. The main focus in this review is the evaluation ...
Bone marrow and lymph node evaluation. Evaluation of equine bone marrow and lymph node samples can provide the definitive diagnosis in some cases, and may provide useful information in other cases. Some newer techniques, including immunophenotyping of cells and clonality assays, provide the capability to more precisely identify cells, both as to origin and malignancy. Use of these techniques on equine bone marrow and lymph node samples, and compiling of the data, will eventually provide invaluable information about equine neoplasia that will greatly improve the ability to predict tumor behavior and response to therapy.
Hypercalcemia and high serum parathyroid hormone-related protein concentration in a horse with multiple myeloma. A 13-year-old gelding was examined because of weight loss, hyperglobulinemia, and hypercalcemia. Possible causes of hypercalcemia that were considered included renal failure, primary hyperparathyroidism, vitamin D toxicosis, and malignancy. There was no history of vitamin D ingestion, and serum creatinine and parathyroid hormone concentrations were normal, making renal failure and primary hyperparathyroidism unlikely. The hypercalcemia was suspected to be a result of malignancy, but thorough testing did not reveal any neoplastic disease. Eight months later, serum parathyroid hormone-related pr...
Metastatic melanoma in horses. The clinical and pathologic findings are reviewed for 14 horses with metastatic melanoma. All were older gray horses, with an average age of 16 years. The most common sites of primary tumors were the ventral tail, perineum, and parotid salivary gland. Metastases were found in multiple locations and caused a variety of clinical syndromes. The most common sites for metastases were the lymph nodes, liver, spleen, skeletal muscle, lungs, and surrounding or within blood vessels throughout the body. Many of the horses had dermal melanomas for years (range 1-6 years) before succumbing to metastatic d...
Hypercalcemia associated with malignancy in a horse. Hypercalcemia associated with malignancy was diagnosed in a 2-year-old Thoroughbred filly admitted because of weight loss and reduced exercise tolerance of approximately 2 months' duration. Laboratory findings included hypercalcemia, hypophosphatemia, anemia, marked neutrophilia with lymphopenia and eosinopenia, and normal immunoreactive parathyroid hormone concentration. At necropsy, a 53.6-kg tumor was located in the cranioventral aspect of the abdominal cavity. Gross renal lesions were not noticed. Bone tissue appeared to be normal on gross and histologic examinations. The parathyroid gland...
Malignant medulloepithelioma of the optic nerve in a horse. An 18-month-old Standardbred filly had a large intraocular tumor involving the optic nerve. The tumor was a malignant medulloepithelioma, a rare intraocular neoplasm derived from the primitive medullary epithelium. By light microscopy the tumor had cords and lobules of primitive neuroepithelial cells that formed clefts and true rosettes. Electron microscopy of the rosettes showed a girdle of zonulae adherentes joining the apices of the cells as well as several basal bodies. This is the sixth report of equine intraocular medulloepithelioma, and, to the best of our knowledge, the first intraocul...