Should cytologists diagnose clear cell papillary renal cell carcinoma on cytologic material?

Abstract

See referenced original article on pages 1-12, this issue.

Diagnostic terminology for benign/low‐risk tumors on renal cytology

“…One of the purposes of biopsy of renal masses is to identify benign and low‐risk tumors in order to offer patients the option of active surveillance 1,2 . According to one study, when given the choice, the majority of patients do elect active surveillance 1 .…”

“…Nevertheless, even though the ROM may be as high as 20% the chance of clinical progression remains low, and such patients may be candidates for active surveillance despite the difficulties in obtaining a definitive diagnosis. The term “low‐risk oncocytic renal neoplasm” has been proposed for this group of tumors 2 …”

The diagnosis of benign renal tumors on limited material

“…The situation for CCPRCT is not as well studied. Even though very specific immunohistochemical features of CCPRCT have been described and previous studies suggest that a definitive diagnosis of CCPRCT can be made on limited material, [12][13][14] our personal experience is that reaching a definitive diagnosis is extremely challenging. Many of these FNA biopsies are paucicellular, presumably because the cells are adherent to the adjacent stroma.…”

“…Fortunately, criteria have already described for AML, [6][7][8][9] papillary adenoma, 1 oncocytoma, 10,11 and CCPRCT. [12][13][14] AML has both characteristic cytologic and immunohistochemical findings that usually allow a definitive diagnosis to be rendered. The cytologic features of papillary adenoma are identical to those of papillary renal cell carcinoma, but by definition are present in a tumor 1.5 cm or less.…”

“…The second consideration for cytologists is what criteria to use to make these diagnoses. Fortunately, criteria have already described for AML, 6–9 papillary adenoma, 1 oncocytoma, 10,11 and CCPRCT 12–14 . AML has both characteristic cytologic and immunohistochemical findings that usually allow a definitive diagnosis to be rendered.…”