Primary Epitheliotropic Intestinal T-cell Lymphoma in a Horse

Abstract

Abstract.A 17-year-old Quarterhorse gelding with a clinical diagnosis of protein-losing enteropathy was submitted for necropsy following a 4-5-month duration of weight loss, decreased appetite, and hypoproteinemia. Gross findings included multiple 1-2-cm diameter ulcers on the luminal surfaces of the duodenum and ileum. Histologic examination revealed individual large, round cells infiltrating much of the mucosal epithelium of the duodenum, jejunum, ileum, and colon in addition to multifocal areas of ulceration. Similar round cells infiltrated Brunner's glands and expanded the submucosa beneath the foci of ulceration. Immunohistochemical staining indicated the round cell population was of T-lymphocyte origin. Several features of this equine neoplasm bear similarities to enteropathy-associated T-cell lymphoma in humans.Alimentary lymphoma in the horse is typically characterized by patchy to diffuse mucosal to transmural intestinal thickenings and infiltration of mesenteric lymph nodes. 2,6,8 In many cases, the neoplastic lymphocytes are suspected, but not demonstrated, to be of B-cell origin, presumably originating from gut-associated lymphoid follicles, 2,8 and predominantly infiltrate the lamina propria and submucosa. Herein we report an equine intestinal lymphoma in which neoplastic cells expressed T-cell, but not B-cell, antigens and were most frequently located within mucosal epithelium.A 17-year-old Quarterhorse gelding presented to the referring veterinarian in October 1999 with a 1-2-month history of weight loss and partial anorexia, which was unresponsive to antibiotic therapy, vitamin B complex, deworming, and dental care. Following a thorough clinical workup, the clinical diagnosis was protein-losing enteropathy, most likely due to small intestinal malabsorption and gastric ulceration. Treatment consisted of dexamethasone, omeprazole, and vitamin supplementation. Although the appetite improved over the next month, the horse failed to gain weight. A second glucose absorption curve revealed 27% improvement, and gastroscopy indicated the gastric ulcers had improved. Over an additional 4 weeks, the horse was able to maintain body weight but remained thin. The horse was euthanized after collapsing in the trailer in transit to the University of Illinois College of Veterinary Medicine, Urbana, Illinois.On gross examination, the horse was emaciated, with serious atrophy of pericardial and mesenteric fat. Present within the parenchyma of the right thyroid gland was a 2-ϫ 1.5-ϫ 1-cm ovoid, gray mass, which bulged at the periphery on sectioning. The abdominal cavity contained approximately 15 liters of clear, watery, pale amber fluid. The thoracic cavity contained approximately 5 liters of clear, watery, pale

Multiple small intestinal pseudodiverticula associated with lymphoma in three horses

“…These findings illustrate the value of immunohistochemistry in cases where the changes are doubtful in routine histological sections. The immunohistochemistry findings in these cases were similar to earlier reports of immunophenotyping of equine lymphomas, suggesting that multicentric, alimentary and mediastinal lymphomas are most frequently of T cell origin (Pinkerton et al . 2002; Meyer et al .…”

Type II EATL (epitheliotropic intestinal T-cell lymphoma): a neoplasm of intra-epithelial T-cells with predominant CD8αα phenotype

“…[28][29][30] It is of interest that a detailed description of a case in a horse did not show features of coeliac disease or jejunitis.…”

Hypertrichosis in a Horse with Alimentary T-Cell Lymphoma and Pituitary Involvement

“…"content-markup(./author-grp [1]/aff|./author-grp [1]/dept-list)> Lymphoma accounts for 0.2 to 3.0% of equine neoplasms. 10 The small intestine is more commonly affected than the large intestine in the alimentary form 7,14,15,18 with secondary involvement of the liver 18 and mesenteric lymph nodes. 15 Clinical signs are usually nonspecific and include weight loss, anorexia, malabsorption, and chronic diarrhea.…”

“…15 Clinical signs are usually nonspecific and include weight loss, anorexia, malabsorption, and chronic diarrhea. 7,14 Equine alimentary lymphoma is usually of Tcell origin. 7,14 Although equine lymphoma involving central nervous system has been documented sporadically, 11 such tumor in the pituitary gland has not been reported.…”

“…7,14 Equine alimentary lymphoma is usually of Tcell origin. 7,14 Although equine lymphoma involving central nervous system has been documented sporadically, 11 such tumor in the pituitary gland has not been reported. This report describes the clinicopathologic findings in a horse with alimentary lymphoma and pituitary involvement.…”