Fig. 1(A) Abdominal computed tomography shows a heterogeneous, well-enhanced mass in the mid-pole of the right kidney (arrowheads). The bilateral renal parenchyma is replaced by multiple, thin-walled cysts. (B) Numerous, variable-sized cysts occupy most of the renal parenchyma. A few solid masses are also identified between the cysts. (C) Fifteen of the 17 solid tumor masses detected during serial section show a well-circumscribed, round to ovoid, variegated appearance, with frequent areas of necrosis and hemorrhage. In contrast, the remaining two masses indicated by arrows display a distinctive gross feature characterized by a whitish tan, solid or granular cut surface without necrosis or hemorrhage. (D) Histologically, clear cell renal-cell carcinoma (RCC) is characterized by an alveolar growth pattern with frequent vascular proliferation. The tumor cells have a round or polygonal shape and clear to eosinophilic granular cytoplasm. (E, F) Papillary RCCs are characterized by a single layer of tumor cells with small nuclei, inconspicuous nucleoli, and pale to basophilic cytoplasm (type 1 papillary RCC; E), and pseudostratified tumor cells with large nuclei, prominent nucleoli, and eosinophilic cytoplasm (type 2 papillary RCC; F).
Table 1Multifocal renal cell carcinoma arising in ADPKD patients1,3,5,11