Acta Vet. Brno 2009, 78: 287-291

Gastrointestinal Stromal Tumour in a Guinea Pig: a Case Report

František Jelínek1, Pavel Hron2, Františka Hozmanová2

1Veterinary Histopathological Laboratory, Prague, Czech Republic
2Veterinary Clinic Erika, Prague, Czech Republic

Received May 27, 2008
Accepted February 9, 2009

The objective of this contribution was to present a case report of gastrointestinal stromal tumour (GIST) in one guinea pig: a pet animal, male, 3.5 year of age, tricolour. Approximately for five weeks before death wasting, in spite of good appetite, decreased locomotor activity, soft and malodorous faeces were observed by the owner. The animal spontaneously died and at necropsy a grey-pink coloured tumour of walnut size located in the terminal segment of the ileum was observed. A solid malignant tumour of mesenchymal appearance was diagnosed histologically. One part of the sample consisted of tightly packed spindle cells arranged in interlacing fascicles, in the other part epithelioid cells predominated with slightly myxoid intercellular matrix. Lymphocytic sheaths were observed around some blood capillaries. Immunohistochemistry revealed positivity for actin, CD 117, neuron-specific enolase, glial fibrillary acidic protein, and p53 protein; however, desmin, S100 protein and synaptophysin were negative. On the basis of histological and immunohistochemical examinations GIST was diagnosed.