Hyaline globules in renal cell carcinoma and hepatocellular carcinoma - A clue or a diagnostic pitfall on fine-needle aspiration?

The cytologic similarly to hepatocellular (HCC) of 2 cases of granular rena l cell carcinoma (RCC) with hyaline globules (HGs) prompted us to evaluate the frequency of HGs in RCC and HCC and the association between cell type, differentiation, and malignant potential of these 2 neoplasms and the prese nce of HGs. We studied fine needle aspirates from 23 cases of RCC(primary, 7; metastatic, 16) and 23 cases of primary HCC and noted anatomic site, tum or cell type, and presence, quality, and quantify of HGs. Fuhrman nuclear g rade was assigned to RCC and overall differentiation to HCC cases. RCC cell type was granular (7), mixed (4), and clear (12). HCC cases were granular (22) and clear (1). Morphologically similar predominantly intracytoplasmic HGs were identified in 4 RCCs and 10 HCCs. All 4 RCCs with HGs were at meta static sites, granular cell type, and high Fuhrman grade. HGs showed no ass ociation with differentiation of HCC. While HGs are seen more commonly in H CC than in RCC, their presence in an adenocarcinoma should bring renal orig in into consideration. The presence of HGs in metastatic granular RCC, part icularly in the fiver; can lead to misinterpretation as primary HCC.