Patho-histological features of fibroblastic sarcoid in horses

Sarcoid is one of the most common skin tumours, which diagnosed in various breeds horses at any age regardless animal’s sex. Such fibroblastic neoplasm manifests itself several clinical ways with its specific morphological features. As a rule, it metastasizes rarely but can be locally invasive. The disease’setiology multifactorial and includes confirmed role bovine papillomavirus genetic environmental factors. article introduces results retrospective study Ukrainian riding breed sarcoid type, was localized mainly area external thoracic vein. Neoplasms were represented by two types. first included broad base neoplasms without pronounced pedicle signs hyperkeratosis. Massive rounded dense formations an ulcerated surface refer to second type. To verify studied types sarcoid, wide surgical excision lesion’svisible parts performed, followed selection fragments for pathohistological diagnosis. Also, additional staining methods used detect connective muscle tissue (Van Gieson’s staining) elastic fibers (Weigert’s resorcin-fuchsin staining). Microscopically, visible showed hyperkeratosis acanthosis peritumoral epidermal layer. Epidermis desquamation significant amount oxyphilic detritus, diapedesis hemorrhages, dilated vessels also detected some areas. Chaotic placement fibroblasts fibrocytes noted, greater extent, subdermally. Anisocytosis anisokaryosis expressed moderately. Sarcoids, macroscopically presented form massive surface, histologically characterized replacement epidermis cellular elements, subdermal characteristic perpendicular orientation coarse collagen towards basement membrane. Closely spaced spindle-shaped cells forming moiré structures visualized deep dermis layers. Nuclei hyperchromic elongated shape, no atypical mitoses noted. Pathohistological examination during identification type diagnostic purposes cause rapid growth formation ulcer. final diagnosis regarding equine made based on combination signs, histopathological examination, molecular testing isolation BPV DNA.