Kidney tumor
Benign (usually) adult tumors
Papillary adenoma

Author: Mandolin Ziadie, M.D. (see Authors page)

Revised: 30 January 2017, last major update March 2012

Copyright: (c) 2003-2017,, Inc.

PubMed Search: "Papillary adenoma" kidney

Cite this page: Papillary adenoma. website. Accessed April 24th, 2017.
Definition / General
  • Low grade (usually) neoplasm also known as renal cortical adenoma
  • Commonly found at autopsy: 10% at age 21 - 40 years, 40% at age 70 - 90
  • Increasing numbers during life are being detected with more widespread whole body imaging
Clinical Features
  • Associated with chronic pyelonephritis, renal vascular disease, von Hippel-Lindau syndrome, long term hemodialysis and acquired cystic disease (in 1/3)
  • Multiple adenomas associated with papillary renal cell carcinoma (Hum Pathol 2007;38:239)
Classification (WHO 2004)
  • Clearly benign: 0.5 cm or less, tubulopapillary architecture
  • Probably benign: same as clearly benign but up to 1 cm
  • Likely malignant: < 1 cm with solid growth pattern or clear cells
  • Malignant: 1 cm or more (Adv Urol 2008:974848)
Case Reports
Gross Description
  • Well circumscribed, unencapsulated pale tumor in subcapsular kidney
  • Usually 0.5 cm or smaller
Gross Images

Images hosted on PathOut server:

1.5 cm subcapsular tumor

Adenoma is 8 cm,
but has benign
histology and is

Images hosted on other servers:

Small, well circumscribed cortical mass

Micro Description
  • Dense papillary / tubular / tubulopapillary architecture composed of small cuboidal cells with scant amphophilic to basophilic cytoplasm, round / oval nuclei (minimal anaplasia - Fuhrman grade 1 / 2) with stippled to clumped chromatin and indistinct nucleoli
  • Variable nuclear grooves, no / rare mitotic figures
  • Psammoma bodies / xanthoma cells may be present
  • Classified as type 1 (basophilic) or type 2 (eosinophilic), based on criteria for papillary renal cell carcinoma
  • Note: small tumors of clear cells are considered to be small renal cell carcinomas, clear cell type and with malignant potential
Micro Images

Images hosted on PathOut server:

Incidental tumor

Xanthoma cells in stroma; type 1 (basophilic) tumors

Tubular structures lined by cuboidal cells with small nuclei

Circumscribed but nonencapsulated tumor

Tiny tumor has papillary architecture

Images hosted on other servers:

Xanthoma cells in stroma; type 1 (basophilic) tumors

Figure A: type 1; Fig B: type 2

Molecular / Cytogenetics Description
  • Gains of #7, 17, 16, 12 and 20 and loss of Y occur early in papillary renal cell neoplasia (Mod Pathol 2003;16:1053)
Molecular / Cytogenetics Images

Images hosted on other servers:

Fig A: single Y present in normal tubules;
Fig B: gain of #12 (3 signals) in papillary adenoma

Additional References