Microscopic and nuclear morphometric findings of chromophobe renal cell carcinoma, renal oncocytoma, and tumor with overlapping histology

We compared the microscopic and nuclear morphometric characteristics of classical chromophobe renal cell carcinoma (C-ChRC) and renal oncocytoma (RO) and applied meaningful characteristics to differentiate eosinophilic chromophobe renal cell carcinoma (E-ChRC) from RO that has overlapping histology (RO-OH) with E-ChRC to know the usefulness of nuclear morphometry. Microscopic and morphometric characteristics were evaluated in 24 C-ChRCs, 6 E-ChRCs, 5 RO-OHs, and 25 classical ROs (C-ROs). The microscopic findings favoring C-ChRC were rasinoid nuclei, perinuclear halo, and distinct cytoplasmic membrane. Characteristic for C-RO was either stromal edema or hyalinization. The morphometric values of nearest nuclear distance, shortest nuclear diameter, and nuclear diameter ratio were significantly different between C-ChRC and C-RO. However, it was impossible to distinguish E-ChRC from RO-OH by histology and nuclear morphometry. The results of our study show that nuclear morphometry and histomorphology can distinguish between C-ChRC and C-RO but not between E-ChRC and RO-OH.