Malabsorption in the Horse associated with Alimentary Lymphosarcoma

Abstract

SUMMARY Three horses suffering from malabsorption were shown to have alimentary lymphosarcoma predominantly affecting the small intestine and the associated lymph nodes. The diffuse cellular infiltration in two of the cases produced marked changes in the villous architecture reducing the available mucosal surface area, and, with lowered or barely detectable disaccharidase activities, contributed to the impairment of digestive‐absorptive processes. One of the horses maintained a voracious appetite and was not diarrhoeic, but failed to gain weight, indicating differences in the production and utilisation of energy sources absorbed from the small and the large intestines. A large proportion of plasma cells in the infiltrate, and the resulting morphological changes in two of the cases bore a striking resemblance to features of alpha chain disease, an immunodeficiency disease of man, although immunological studies were not conducted on these horses. RÉSUMÉ Trois chevaux souffrant de malabsorption se révèlèrent souffrir d'un lymphosarcome affectant surtout l'intestin grêle et les ganglions lymphatiques correspondants. Pour deux cas l'infiltration cellulaire diffuse produisit des altérations prononcées de la structure des villosités, entrainant une diminution de la surface muqueuse disponible. Ceci, avec un abaissement plus ou moins appréciable du taux de disaccharidase, contribua à détériorer les fonctions de digestion‐absorption. L'un des chevaux conserva un grand appétit et ne montra point de diarrhée, mais ne put reprendre de poids, suggèrant l'existence de différences entre l'intestin grêle et le gros intestin, comme facteur de production et d'utilisation de l'énergie. Une grande partie des cellules infiltrées d'une part, et d'autre part les modifications morphologiques présentées par deux des trois cas évoquent de fačon frappante une maladie de l'homme, par déficience immunitaire. ZUSAMMENFASSUNG Drei Pferde mit Malabsorption litten an einem Lymphosarkom des Verdauungstraktes, das vor allem im Dünndarm und den dazugehörenden Lymphknoten anzutreffen war. Die diffuse, zelluläre Infiltration in zwei Fällen verursachte deutliche Veränderungen in der Struktur der Villi mit einer Reduktion der Schleim‐hautoberfläche. Bei einer herabgesetzten oder kaum nachweisbaren Disaccharidaseaktivität trugen diese Veränderungen zu einer Beeinträchtigung der digestiven‐absorptiven Vorgänge bei. Eines der Pferde zeigte einen gierigen Appetit und war nicht diarrhoisch, nahm jedoch nicht an Gewicht zu, was einer Abweichung in der Produktion und Verwendung der Energiequellen, absorbiert aus Dünn‐ und Dickdarm, zugeschrieben wurde. Ein grosser Anteil von Plasmazellen im Infiltrat und die resultierenden morphologischen Veränderungen in zwei Fällen ähnelten sehr stark der sogenannten Alpha‐Ketten‐Krankheit, einer menschlichen Immunkrankheit, aber immunologische Untersuchungen wurden bei diesen Pferden nicht durchgeführt.

Multiple small intestinal pseudodiverticula associated with lymphoma in three horses

“…The clinical progression of the disease in these 3 horses was rapid following the onset of clinical signs, consistent with previous reports of alimentary lymphoma (Roberts and Pinsent 1975; Wilson et al . 1985; Platt 1987; Carlson 1995; Hillyer and Mair 1997; East and Savage 1998; Taylor et al .…”

“…Most previous reports of alimentary lymphoma in the horse have described focal intestinal and/or mesenteric masses (usually involving the small intestine and often associated with infiltration and enlargement of mesenteric lymph nodes) or patchy to diffuse mucosal or transmural thickening associated with infiltration of the intestinal wall (Platt 1987). Ulcers of the intestinal mucosa, sometimes with necrotic centres, have been previously reported in association with lymphoma (Roberts and Pinsent 1975; Wilson et al . 1985; Herraez et al .…”

“…2006). The alimentary form of lymphoma most commonly affects the small intestine and can develop as diffuse intestinal infiltrates associated with weight loss and small intestinal malabsorption; focal intestinal or mesenteric masses associated with weight loss and abdominal pain; or combinations of these lesion types (Roberts and Pinsent 1975; Wilson et al . 1985; Platt 1987; Carlson 1995; Hillyer and Mair 1997; East and Savage 1998; Taylor et al .…”

Ultrasound as a diagnostic tool in the investigation of a pony with intestinal lymphoma

“…). Grossly, mucosal ulceration, possibly with necrotic centres, has previously been noted in horses with lymphoma (Roberts and Pinsent ; Wilson et al . ; Herraez et al .…”

Equine lymphoma: What are the prospects for cellular differentiation, early diagnosis and intervention strategies?

“…malabsorption, Roberts and Pinsent 1976). Lymphoma is considered the most frequently encountered neoplasm of the equine haematopoietic system, and is grouped into 4 presentations involving primarily lymph nodes (multicentric), or extranodal sites (skin, thymus or alimentary tract).…”