Abstract
Spontaneous cutaneous mastocytomas in Djungarian hamsters (D-hamster) were pathologically studied and compared with those in canine and feline cases. Eight (9.3%) of 86 cutaneous biopsy cases in D-hamsters were diagnosed as mastocytomas, being slightly higher in incidence than in canine and feline species. In 4 of 8 D-hamster cases, the tumor lesions were in the head and neck in contrast to most canine lesions in the extremities. The histopathology of the D-hamster mastocytoma was characterized by diffuse or massive proliferation of well-differentiated tumor cells with severe degeneration of collagen fibers and slight eosinophil infiltration in most cases.