Hair follicle tumors in dogs: A report of two cases

The single case each of trichoblastoma and trichoepithelioma in mixed breed of dog is reported. Microscopic examination of trichoblastoma revealed, the presence of polygonal basaloid cells arranged in nests and islands and were separated by a moderately dense collagen fibrous stroma. Neoplastic cells had indistinct cell borders and eosinophilic, cytoplasm with centrally located nuclei. Histopathologic evaluation of trichoepithelioma revealed, multilobulated neoplasm composed of multiple keratin filled cysts lined by basophilic basaloid cells, showed abrupt and gradual keratinization and separated by a moderate fibrovascular stroma. Neoplastic cells formed incomplete or abortive hair follicle.