Rare renal neoplasms in Salmo gairdneri exposed to MNNG (N-methyl-N'-nitro-N-nitroso-guanidine)

Abstract

N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) is a potent liver, stomach, kidney, and swimbladder carcinogen in rainbow trout Salmo gairdnen. Histopathological examination of tissues from trout exposed as fry to 50 ppm MNNG for 30 min revealed 2 types of neoplastic renal lesions not previously reported for this species. Renal cell carcinoma in the corpuscle of Stannius and renal cell, cystic, papillary adenoma of the mesonephric duct were diagnosed. Nephroblastoma and nephrocalcinotic lesions adjacent to the mesonephric duct adenoma suggested that occlusion of the duct could have been a contributing factor