Background and purpose: Clear cell papillary renal cell carcinoma is a rare renal epithelial malignant tumor which was recently discovered. Its biological behavior is inert

and its prognosis is good. The purpose of this article was to analyze the clinical and pathological features of clear cell papillary renal cell carcinoma

and differentiate it from other subtypes to avoid overtreatment. Methods: Seven cases of clear cell papillary renal cell carcinoma were collected and analyzed by histopathology and immunohistochemistry. Results: In 7 cases

the masses were all located in the kidneys. The incised surface was grayish red and grayish yellow

solid or cystic. Under the microscope

the tumor tissue was glandular tubular

microcystic

or papillary. The tumor could be a dominant structure or a variety of structures mixed presence. The cytoplasm was clear

the nucleus was round or ovoid

and WHO/ISUP grading was grade 1 or 2. Immunophenotype results showed that 7 cases all expressed CK7

CK8

vimentin

PAX-8

CA9

CK34βE12

and Ki-67 proliferative index 5 % -10 %. However

none of them expressed CD117

TFE3 or CD10. All the patients were followed up for 2 months to 4 years without recurrence or metastasis. Conclusion: Clear cell papillary renal cell carcinoma is a rare low-grade malignant tumor. Morphologically

it overlaps with a variety of renal cancers with clear cells and/or papillary cells

which can be differentiated by immunohistochemistry.