Possible Intraspinal Metastasis of a Canine Spinal Cord Nephroblastoma

Abstract

Abstract.A 2-year-old Basset Hound was admitted to the University of Florida Veterinary Medical Teaching Hospital with progressive spastic paraparesis. At necropsy, intradural extramedullary tumors produced areas of spinal cord swelling and softening in spinal cord segments T11-T12 and L4-L6. Histologic examination of the masses revealed sheets of polygonal blastemal cells, epithelial cells forming tubules and rosettes, and embryonal glomeruloid-like structures in the thoracic mass. Cells in the lumbar mass were less differentiated, forming rare tubules and no glomeruloid-like structures. The occurrence of two tumors in the spinal cord along with the less differentiated appearance of the lumbar tumor raises the possibility that the lumbar mass arose as a result of intraspinal metastasis. To our knowledge, this is the first report of multifocal or metastatic canine spinal nephroblastoma. In addition, the vimentin and cytokeratin immunohistochemical staining characteristics of these spinal cord nephroblastomas are described.

Nephroblastoma with Transcoelomic Metastasis in a Japanese Black Bull

“…Our immunohistochemical findings were consistent with human and canine nephroblastomas [7,9,11], except for the positive results of blastemal cells for cytokeratin. Neoplastic blastemal cells are generally positive for vimentin [7,9,11] and usually lack other differentiation markers [7]. However, during the normal nephrogenesis, blastemal cells cause antigenic shift from vimentin to cytokeratin [5].…”

“…However, the histological appearance in the present case was unique in that blastemal and stromal elements predominated in primary and metastatic lesions. In human and canine nephroblastomas, blastemal cells are mitotically active and show aggressive growth [7,9,11]. Therefore, the amount of blastemal elements may be associated with the malignancy of nephroblastomas.…”

Tumors of the Nervous System

“…120 Dogs with spinal nephroblastomas can be treated effectively with a combination of surgery and RT. 123 A report of two dogs with intramedullary spinal cord hemangioma included information on one dog treated with lomustine (no histologically and biologically aggressive masses. 111,112,122 It should be noted that since this is a tumor that develops in young dogs, RT carries the risk for the development of radiation-induced tumors.…”

Proliferative Potential of a Spinal Nephroblastoma in a Young Dog

“…Spinal nephroblastomas likely develop from the remnants of renal rests trapped between the dura and the developing spinal cord 1,2,5,7 . Regarding the biological behavior of this tumor, little information is available except for a report of an aggressive neoplasm giving rise to a second, less differentiated metastatic focus 5 . We endeavored to assess the proliferative potential of a spinal nephroblastoma in a young dog.…”