Expression pattern of tumor markers in canine hemangiopericytoma

Hemangiopericytoma is a common vascular neoplasm of dog thought to be derived from pericytes. A study was undertaken on 15 canine tumors selected from biopsy and necropsy (N) submissions for the period 2004 to 2016 of dogs in Grenada which were diagnosed histologically as canine hemangiopericytomas. Immunohistochemistry was performed on nine (9) cases to determine the reactivity for vimentin, cytokeratin, chromogranin A, c-Myc, and p53. All 9 cases (100%) showed reactivity for vimentin and four cases (44.4%) were positive for c-Myc. All cases were uniformly nonreactive for cytokeratin, chromogranin A and p53. Since vimentin is a protein expressed in mesenchymal cells, further studies using more tumor markers are indicated to differentiate canine hemangiopericytoma from other mesenchymal sarcomas.