Anaplastic nephroblastoma with peritoneal metastasis in an adult female Sprague Dawley rat

Abstract

Spontaneous nephroblastomas are uncommon tumors of laboratory rats. This report describes a spontaneous nephroblastoma with peritoneal metastasis in an 11-month-old, female Sprague Dawley rat. The rat was part of a breeding program and presented 15 days post parturition with clinical signs including tachypnea, dyspnea and abdominal distension. At necropsy, the right kidney was markedly enlarged by an expansile pale-tan to white multinodular mass with extension into the retroperitoneal space, with multifocal variably sized cystic nodules involving the mesentery, and surface of pancreas, liver, uterus, and ovarian bursa. The rat also had severe bicavitary effusion. Histologically, the renal parenchyma of the affected kidney was replaced by a moderately cellular, poorly-demarcated, nonencapsulated, multilobulated mass that appeared to compress the adjacent renal outer medulla and cortex. Three distinct neoplastic cell populations were identified in this renal tumor: epithelial cells (convoluted and dilated tubules / rare primitive glomeruloid structures), mesenchymal (neoplastic spindle cells in connective tissue), and blastemal cells (primitive neoplastic cells). The extrarenal nodular masses were predominantly composed of neoplastic mesenchymal and pleomorphic blastemal cells. Immunohistochemically, neoplastic epithelial cells in the renal mass were positive for pancytokeratin, and blastemal cells in both renal and extrarenal masses were positive for Wilms tumor 1 protein (WT1) and vimentin. Neoplastic mesenchymal elements in both renal and extrarenal masses were positive for vimentin. The neoplasm was negative for chromogranin A and S100. The tumor was classified as an anaplastic nephroblastoma with metastasis to the mesentery and peritoneal organs.

The Effect of Propofol on the Proliferation of Nephroblastoma Cells and the Underlying Mechanism

“…The current global overall survival rate is as high as 70% to 80%, and it may even be higher [4]. The possibility of malignant metastasis still exists in the terminal stage of nephroblastoma, and the mortality rate is still as high as 5% [5]. Therefore, looking for the mechanism of the occurrence and development of nephroblastoma is of great significance to the occurrence and development of the intervention treatment of the disease and the improvement of the cure of the disease.…”