Abstract: Objective: To investigate the clinicopathological characteristics of the solid papillary renal cell carcinoma(sPRCC),and its differential diagnosis from mucinous tubular and spindle cell carcinoma(MTSC).Methods: Two sPRCC cases were investigated by light microscopy,special stains,immunohistochemistry,fluorescence in situ hybridization(FISH),and the literature was reviewed.Results: Two sPRCC patients were male,51 and 71 years old,the lumbago was their clinical manifestation.The tumor size of two cases were 2.0 cm and 3.5 cm,the cut surface of tumors were grayish-white,well-circumscribed,and local hemorrhage and necrosis.Histological examination of two tumors showed that the tumor cells were cuboidal or oval and arranged in tubular pattern,and the part cells tightly packed and arranged in solid sheet.The partial region tumor cells in 1 case arranged in beam,a small amount of papillary structures without vascular axis were found in tumor margin,and a small amount of slime and sand body calcification corpuscle were found in intercellular substance.Foam cell aggregation and mucous mesenchyme in intercellular substance were found in another case.The positive expressions of AMACR,Vimentin,EMA,CK7 and CK19 were found in two cases,and the Ki-67 was less than 5%.FISH showed that chromosomes 7 and 17 amplified,and chromosomes Y lost in two cases.Conclusions: The sPRCC is rare papillary renal cell carcinoma,the morphology and immunohistochemistry of which are similar with MTSC.The FISH examination can effectively identify the sPRCC from MTSC.