Study on skin neoplasms on Rutillus frisii kutum in the Caspian Sea

Objective: Many of neoplasms observed on fish are skin tumors and these are predominantly papillomas. This study was carried out in order to determine superficial neoplasm presence in Rutillus frisii kutum for tow years. Neoplasia in various species of fishes including freshwater, brackish water and marine fishes was reported but up to now there is no documented report of Rutillus frisii kutum tumor in Iran. This study was performed in Guilan Province area during 2006 – 2007. Method & Materials: In 46 times catching kutum in beach seine cooperatives, we observed all fishes in order to any abnormal mass which is suspicious to neoplasia and we found 5 neoplastice cases with lesion on dorsal and ventral lips. Suspicious lesions were fixed in 10 percent formalin buffer and after histotechnique processing was stained with H & E then histopathologically were examined. Results & Conclusion: In microscopic study of lesions, extensive hyperplasia of malpigian celles and strong hyperplastic thickening was observed. The number of undifferentiated epidermal cells with similar shape and mitotic stages was significantly increased while the mucous cells and club cells were greatly reduced in number and size. In some areas a few infiltration of lymphoid cells were observed. There was a core of vascular tissue for serving the extensive new growth. In collusion all of 5 lesions were Squamous cell papilloma.