An adult water chevrotain was euthanized due to severe non-responsive pododermatitis. Incidentally, multiple to&nbsp;coalescing cholesterol granulomas were identified within the right diencephalon, characterized by the presence of foamy macrophagesand cholesterol clefts consistent with encephalic xanthomas. No clinical signs or predisposing conditions associated with this findingwere identified. This is the first known report of encephalic xanthomas in this species

Carvallo, Francisco R.

González, María F.

Pardo, Ingrid D.

Sisó, Silvia

English

Austral Journal of Veterinary Sciences

209Austral J Vet Sci 49, 209-211 (2017)CASE REPORTAccepted: 02.05.2017.aFacultad de Recursos Naturales y Medicina Veterinaria, Universidad Santo Tomás, Talca, Chile.bDepartment of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, USA.cDrug Safety, Research and Development, Pfizer Inc., Groton, USA.dCalifornia Animal Health and Food Safety Laboratory, University of California, Davis, USA. *Corresponding author: F Carvallo; 105 W Central Ave, San Bernardino, CA 92408, USA; fcarvallo@ucdavis.eduEncephalic xanthomas in a large malayan chevrotain (Tragulus napu)María F. González, Silvia Sisób, Ingrid D. Pardoc, Francisco R. Carvallod*ABSTRACT. An adult water chevrotain was euthanized due to severe non-responsive pododermatitis. Incidentally, multiple to coalescing cholesterol granulomas were identified within the right diencephalon, characterized by the presence of foamy macrophages and cholesterol clefts consistent with encephalic xanthomas. No clinical signs or predisposing conditions associated with this finding were identified. This is the first known report of encephalic xanthomas in this species. Key words: brain, cholesteatoma, cholesterol granuloma.RESUMEN. Un ciervo ratón grande adulto es eutanasiado debido a una pododermatitis que no responde al tratamiento. Incidentalmente, se identifican numerosos granulomas de colesterol en el diencéfalo derecho, los que se caracterizan por la presencia de macrófagos espumosos y cristales de colesterol, consistentes con xantomas cerebrales. No se identificaron signos clínicos o condiciones predisponentes asociados con este hallazgo. Este es el primer reporte de xantomas cerebrales en esta especie. Palabras clave: cerebro, colesteatoma, granuloma de colesterol.A 15 year–old, male large malayan chevrotain (Tragalus napu) kept in captivity was euthanized and presented for necropsy due to severe chronic pododermatitis which did not improve with treatment. Necropsy findings included suppurative pododermatitis, from which Pasteurella multo-cida was isolated, and also bilateral congenital renal cysts. In the brain, a 0.5 × 0.2 white linear lesion was identified in the right ventral thalamus, involving the optic tract and in close proximity to the crus cerebri (figure 1). Representative samples of multiple organs were collected and fixed in 10% neutral buffered formalin. After routine paraffin embedding, 4 µm thick hematoxylin and eosin (H&E) sections were prepared. In addition, selected sections of the brain were stained with Ziehl-Nielsen, luxol fast blue and Periodic acid Schiff stains. At the junction of the right thalamus and the cerebral cortex, there were numerous coalescing granulomas embedded within the gray and white matter areas, composed of sheets of foamy macrophages contain-ing a granular, faintly eosinophilic granular cytoplasmic material (figure 2). Granulomas contained large numbers of acicular cholesterol-like crystals, a few lymphocytes and occasional neutrophils. Immunohistochemistry for CD-204 strongly labeled the cytoplasm of foamy cells, confirming their histiocytic origin (figure 2, inset). Granulomas within white matter tracts, i.e. optic tract, were not associated with myelin loss since no reduction of myelin was observed in sections stained with luxol fast blue. Other sections of the brain also displayed very small aggregates of foamy cells, but no crystals were delineated. No acid-fast bacteria or fungal organisms were recognized in any of those lesions. No cholesterol granulomas were identified in any of the other examined tissues. With this information, a diagnosis of encephalic cholesterol granulomas (encephalic xantho-mas) was reached.Xanthomas (Greek “xanthos”, meaning yellow), also called xanthogranulomas, cholesteatomas or cholesterol granulomas, are rare non-neoplastic masses composed of large foamy macrophages, containing clear vacuoles in cytoplasm, Touton type mononuclear giant cells with eccentric nuclei, abundant material and cholesterol clefts, and less frequently with the presence of lymphocytes and fibrosis (Ozmen and Holigur 2011, Kheirandish et al 2013, Mauldin and Peters-Kennedy 2016). Although these lesions are not neoplastic, it can invade locally (Kheirandish et al 2013). Xanthomas have been reported in human and mul-tiple animal species, in which the most frequent locations are the skin, sub cutis and tendon sheaths, but other tissue can also be affected. In humans, xanthomas are a common feature of cerebrotendinous xanthomatosis, which has been associated with an autosomal recessive mutation of the CYP27A1 gene encoding a cytochrome p450 oxidase, and causes a defect of the sterol 27-hydroxylase enzyme (Björkhem 2013).In animals, encephalic xanthomas have been described in Cuban tree frogs (Carpenter et al 1986), geckos (Garner et al 1999), green water dragons (Kummrow et al 2010), a dog (Cramer et al 2011), meerkats (Sladky et al 2010) and horses (Summer et al 1995, Cantile and Youseef 2016). In these animals, the xanthomas were located principally in the ventricles, hypothalamus, pituitary gland and in the white matter of the spinal cord, not always associated with neurologic signs. When present, clinical signs depend on the location of the lesions, and include decreased motor activity, opisthotonus, horizontal head bobbing and inco-ordination (Carpenter et al 1986, Kummrow et al 2010). 209210GONZÁLEZ ET ALThe pathogenesis of xanthomas is not clearly understood, but disorders in lipid metabolism and metabolic disease have been postulated (Kheirandish et al 2013, Ravens et al 2013). In humans, dogs and cats, xanthomas have been associated with hyperlipidemia (Wisselink et al 1994, Banajee et al 2011, Ozmen and Haligur 2011, Kheirandish et al 2013) as well as other factors such as diabetes mellitus, glucocorticoid therapy or high cholesterol diets (Wisselink et al 1994, Mauldin and Peters-Kennedy 2016), hypothyroidism, hyperadrenocorticism, genetic factors and systemic diseases (Cramer et al 2011, Lipar et al 2011, Kheirandish et al 2013). In horses, choroid plexus cholesterol granulomas are frequent in old animals and appear to be initiated by chronic congestion, edema and hemorrhage into the plexus stroma. Infiltration of macrophages containing lipid and hemosiderin follows, with deposits of cholesterol clefts which could act as a foreign body, triggering low grade inflammation (Cantile and Youseef 2016). In the water chevrotain described here, lesions were found at the margin of the right thal-amus, sparing the choroid plexuses. These lesions were not associated with neurological signs. Additionally, blood cholesterol levels were within normal range for the species, and there was no previous history of cerebral trauma or trauma-related microscopic lesions.In conclusion, to the authors’ knowledge, this is the first published report of encephalic xanthomas in a water chevrotain. In this case, the described lesion was considered an incidental finding. The pathogenesis of this condition remains unclear.ACKNOWLEDGEMENTSThe authors acknowledge Mrs. Sue Ellen Uzal and Dr. Francisco Uzal for the English review of this manuscript.REFERENCES Banejee KH, Orandle MS, Ratteree W, Bauer RW, Gaunt ST. 2011. Idiopathic solitary cutaneous xanthoma in a dog. Vet Clin Pathol 40, 95-98.Björkhem I. 2013. Cerebrotendinous xanthomatosis. Curr Opin Lipidol 24, 283-287.Cantile C, Youssef S. 2016. Nervous System. In: Maxie MG (ed). Jubb, Kennedy and Palmer’s Pathology of domestic animals. 6th ed, Vol 1. Elsevier Saunders, Philadelphia PA, USA, Pp 250-406.Carpenter JL, Bachrach Jr A, Albert DM, Vainisi SJ, Goldstein MA. 1986. Xanthomatous keratitis disseminated xanthomatosis, and atherosclerosis in Cuban tree frogs. Vet Pathol 23, 337-339.Cramer SD, Miller AD, Medici EL, Brunker JD, Ritchey JW. 2011. Sellar xanthogranuloma in a dog. J Vet Diagnost Invest 23, 387-390.Garner MM, Lung NP, Murray S. 1999. Xanthomatosis in geckos: five cases. J Zoo Wildl Med 60, 443-447.Kheirandish R, Azizi S, Azari O. 2013. Cutaneous xanthoma in a do-mestic pigeon: pathologic study (case report). Glob Vet 10, 140-143.Kummrow MS, Berkvens CN, Paré JA, Smith DA. 2010. Cerebral xan-thomatosis in three green water dragons (Physignathus cocincinus). J Zoo Wildl Med 41, 128-132.Lipar N, Horvatek D, Prukner-Radov i  E, Kurilj AG, Radiši  B, et al. 2011. Subcutaneous xanthoma in a cockatiel (Nymphicus hollandi-cus) - a case report. Vet Arhiv 81, 535-543.Mauldin EA, Peters-Kennedy J. 2016. Integumentary system. In: Maxie MG (ed). Jubb, Kennedy and Palmer´s Pathology of domestic animals. 6th ed, Vol 1. Elsevier Saunders, Philadelphia PA, USA, Pp 509-736.Ozmen O, Haligur M. 2011. A case of xanthoma in a Saanen goat. Vet Dermatol 23, 150-152.Figure 2. Thalamus displaying two coalescing granulomas, composed of numerous foamy macrophages lining the silhouet-tes of cholesterol clefts. Hematoxylin and eosin, 400X. Inset: CD-204 Immunohistochemistry labeling the cytoplasm of foamy cells, confirming their histiocytic origin. Meyer’s Hematoxylin counterstain, 200X.Figure 1. Transverse section of the brain (thalamus) with the presence of a linear white lesion in the right ventral thalamus (arrow). 211BRAIN, CHOLESTEATOMA, CHOLESTEROL GRANULOMARaven PA, Vogelnest LJ, Piripi SA. 2013. Unique presentation of normalipaemic cutaneous xanthoma in a cat. Aust Vet J 91, 460-463.Sladky KK, Dalldorf FG, Steinberg H, Wright JF, Loomis MR. 2010. Cholesterol granulomas in three meerkats (Suricata suricatta). Vet Pathol 37, 684-686. Summer BA, Cummings JF, de Lahunta A. 1995. Principles of Neuropathology. In: Summer BA, Cummings JF, de Lahunta A (eds). Veterinary Neuropathology. Mosby, St. Louis MO, USA, Pp 1-67. Wisselink MA, Koeman JP, Wensing T, de Bruijne J, Willemse T. 1994. Hyperlipoproteinaemia associated with atherosclerosis and cutaneous xanthomatosis in a cat. Vet Quart 16, 199-202.

Encephalic xanthomas in a large malayan chevrotain (Tragulus napu)

https://ajvs.cl/index.php/ajvs/article/download/134/121

Encephalic xanthomas in a large malayan chevrotain (Tragulus napu)

Abstract

Similar works

Full text

Available Versions

Austral Journal of Veterinary Sciences