The expression of heterochromatin protein 1α/β in the kidney tumors: a microarray immunohistochemical study

Kidney tumors of various types may behave differently and have different prognosis. Due to some overlapping morphological features and immunohistochemical staining pattern, they may pose diagnostic challenge. Therefore, it is necessary to explore additional immunohistochemical stains to help in subclassifying these epithelial neoplasms. Tissue microarrays of 20 cases each of renal cell carcinomas (RCC) of clear cell, chromophobe, and papillary variants and oncocytoma were constructed and used to test the heterochromatin-associated protein (HP) 1α/β expression. HP-1α/β showed strong nuclear staining. Expression of HP-1α/β was found mostly in papillary RCC (79%) and oncocytoma (75%) but less in chromophobe (30%) and clear cell RCCs (35%). HP-1α/β may be useful in the differential diagnosis of renal tumors, especially in the differentiation of chromophobe RCC and oncocytoma.