The diagnosis of benign renal tumors on limited material

Abstract

Angiomyolipoma, papillary adenoma, oncocytoma, and clear cell papillary renal cell tumor are common benign renal tumors that may be encountered on biopsy material. The diagnostic criteria, limitations, and accuracy as well as specific sign out terminology are reviewed.

Role of renal mass biopsy for diagnosis and management: Review of current trends and future directions

“…It is important to note that there are entities for which a definitive diagnosis can be made on both FNA and core biopsy material. Conversely, there are other entities for which a definitive diagnosis cannot be reached on either FNA or core biopsy material because it is not possible to entirely exclude other entities on the differential diagnosis based on biopsy material alone 44 . A systematic review reported a pooled positive predictive value of 99.8% and negative predictive value of 68.5% for RMB 14 …”

“…Sufficient material on the cell block or core biopsy is important to properly assess the morphology and perform immunohistochemistry and/or special staining to establish an unequivocal diagnosis. 44,76,78 Caution is advised when the specimen is limited and ancillary studies are not definitive. Reporting oncocytic neoplasm, favor oncocytoma with a comment stating that RCC cannot be entirely ruled out is recommended under these circumstances.…”

“…When evaluating an oncocytic renal neoplasm on small biopsy specimens, there is a possibility that the biopsy‐sampled areas of an RCC that are morphologically similar to an oncocytoma. Sufficient material on the cell block or core biopsy is important to properly assess the morphology and perform immunohistochemistry and/or special staining to establish an unequivocal diagnosis 44,76,78 . Caution is advised when the specimen is limited and ancillary studies are not definitive.…”

Risk of malignancy in renal biopsy: A review

“…Whether this diagnosis can be made on cytologic material (including both fine-needle aspiration and core-needle biopsy) remains controversial. 9,12,19 However, if a benign diagnosis can be made, the majority of patients opt for active surveillance. 8 The largest series to date demonstrated an ROM for the diagnosis of oncocytoma on fineneedle aspiration, core-needle biopsy, and immunohistochemistry of 2%.…”

“…However, when given a benign, diagnosis most patients chose active surveillance rather than definitive therapy 8 . Consequently, the ability to give a reliable benign diagnosis is critical in biopsy interpretation 9 …”