PERIPHERAL NEUROBLASTOMA AND PRIMITIVE NEUROECTODERMAL TUMOR IN JAPANESE BLACK CATTLE

Peripheral neuroblastoma was found in a 1-year-old, male, Japanese bla ck cattle (Case 1) and primitive neuroectodermal tumor was noted in 7- year-old, female, Japanese black cattle (Case :2). In Case 1, neoplast ic tissue was replaced the right cranial vault and nasopharynx. A larg e, soft mass approximately re, cm in diameter was also observed in the right mandibulopharyngeal area. In Case 2, a neoplastic mass of about 15 cm in diameter was found in the mandibulopharyngeal area. Histopat hologically, massive necrosis showing a pseudopalisade arrangement was frequently observed in Case I. On the contrary, Homer & Wright rosett e formations of tumor cells were prominent in Case 2. Immunohistochemi cally, the proliferating cells in Case were positive for vimentin, S-1 00, and neurofilament (NF) and those in Case 2 showed intense immunore activity for MF and neuron specific enolase, but were negative for vim entin and S-100. The different degrees of differentiation of the neopl astic cells originating from the neuroectoderm, might be reflected in their different morphological and immunohistochemical features.