Intranuclear Inclusions in Conventional Clear Cell Renal Cell Carcinoma (ccRCC): Diagnosis and Differential Diagnosis.

Intranuclear inclusions are important diagnostic features in many benign and malignant neoplasms. It has also been identified in major epithelial subtypes of renal cell carcinomas (RCCs), particularly in the chromophobe RCC. However, the finding in ccRCC has not been well studied. The finding of intranuclear inclusions may cause diagnostic difficulty, particularly in metastatic lesions. Herein, we reported a case of ccRCC with prominent intranuclear inclusions. The tumor also metastasized to local lymph nodes. Furthermore, in contrast to previous publications, we also found that intranuclear inclusions were immunoreactive with anti-PAX8 (paired box8) antibody. The potential diagnostic and clinical implications of intranuclear inclusions in ccRCC need to be addressed.