Cholesterol granuloma (plexus cholesteatoma) in a horse -: Case report

The authors diagnosed cholesterol granulomas (plexus cholesteatomas) in the plexus of lateral ventricle in an 8 years old Arabian mare, growing symmetrically and causing frequent and sever neurological signs. Condition of mare had worsened for months, despite normal feed and water consumption. In the last month her movement and behaviour changed, became slow and anxious. During moving in and out of stable, one person led and another one forced her. She frequently went against the wall and was shy and apathic. During dissection, in the plexus chorioideus ventriculi lateralis small-egg-sized, oval, compact, slightly tubercle-surfaced, greyish-brown tumour-like formation was found (Figure 1), which were freely moveable in the ventricle and connected to tissues of plexus 1:Figure 2). On the section of formations fibrous septa and between them crystal-like elongated forms were found. Lateral ventricles were consequently dilated and surrounding brain parts atrophied. During histopathological examination a structure confined by collagen fibrous capsule of different width (200-800 mu m) and divided into compartments by fibrous septa of 15-30 mu m Was visible (Figure 3), the empty gaps of which indicate the places of dissolved cholesterol tables. Cholesterol tables showed double refractive characteristic in native uncoloured preparation by polarisation microscopic examination,On the basis of negative laboratory examination results, beside rabies, Borna-disease, important from differential diagnosis point of view and chronic form of leucoencephalomalatia caused by fumonisine B-1 were excluded.