October 2007

Cat Skin, Dermis: Eosinophilic Granuloma

Feline eosinophilic granuloma complex (EGC) is a common inflammatory skin disease which incoporates a group of lesions that affect the skin, mucocutaneous junctions, and oral cavity. EGC is composed of a group of lesions which classically included three lesions namely the indolent ulcer, the eosinophilic plaque, and the eosinophilic granuloma. Note the centrally degranulated eosinophilic material surrounded by macrophages and multinucleated giant cells. An underlying hypersentitivity reaction has often been associated with these lesions.

November 2007

Donkey, brain, Hippocampus: Hepatic encephalopathy

Donkeys like horses can suffer with increased circulating ammonia levels due to severe liver disease. High magnification views of hippocampal neuropil shows significant enlargement of astrocyte nuclei, often equal or exceeding the size of neuronal nuclei.

December 2007

Cat, Inguinal lymph node: Plexiform vascularisation

A distinctive lymphadenopathy in cats is characterized by capillary vasoproliferation and lymphoid atrophy. It occurs in the cervical or inguinal regions. The animals are usually, apart from local manifestations, healthy. An ischaemic pathogenesis for the lesions which may be related to human "vascular transformation of lymph node sinuses" has been made. The lesions appear to be infrequent cause of non-neoplastic lymphadenopathy in domestic cats, as they constituted only 5 per cent of surgical biopsies of cat lymph nodes seen in the past 5 years in one report. Surgical excision is usually curative.