| Sign In to gain access to subscriptions and/or personal tools. |
Malignant Myopericytoma-like Tumor in a Fischer RatLaboratory of Pathology, Toxicology Division, The Institute of Environmental Toxicology, Uchimoriya-machi 4321, Joso-shi, Ibaraki, Japan Correspondence: Naofumi Takahashi, DVM., Laboratory of Pathology, Toxicology Division, The Institute of Environmental Toxicology, Uchimoriya-machi 4321, Joso-shi, Ibaraki 303–0043, Japan; e-mail:n.takahashi{at}iet.or.jp. Myopericytoma is a perivascular tumor that has been recently described in humans, but not in laboratory rodents. The authors encountered an intra-abdominal tumor resembling human malignant myopericytoma in a Fischer rat. Grossly, the tumor was found as two brown-colored masses located in the mesentery of rectum. Microscopically, the tumor was composed of oval to spindle-shaped cells, which were arranged in sheets around numerous thin-walled branching vessels and partly showed a concentric perivascular growth pattern. Mitoses were frequently seen, and the tumor cells showed a local invasion. Immunohistochemically, the tumor cells were strongly positive for alpha-smooth muscle actin and weakly positive for vimentin and desmin. Ultrastructurally, the tumor cells had dendritic processes, actin-like thin filaments with dense bodies, basement membranes, hemidesmosomes, and micropinocytotic vesicles. These findings suggest that the most appropriate term for diagnosis of the present case could be a malignant myopericytoma.
Key Words: malignant myopericytoma • perivascular tumor • myopericyte • Fischer rat Abbreviations: WHO, World Health Organization
This version was published on July
1, 2008 Toxicologic Pathology, Vol. 36, No. 5,
738-742 (2008) |
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
|
|
 |
|
Sign In to gain access to subscriptions and/or personal tools.
