Kidney tumor
Adult renal cell carcinoma - common
Papillary type 1

Topic Completed: 1 October 2017

Minor changes: 10 December 2020

Copyright: 2003-2019,, Inc.

PubMed Search: Type 1 (basophilic) papillary renal cell carcinoma

Related topics: Papillary type, renal cell carcinoma, type 2, solid growth pattern

Nicole K. Andeen, M.D.
Maria Tretiakova, M.D., Ph.D.
Page views in 2020: 8,194
Page views in 2021 to date: 610
Cite this page: Andeen NK, Tretiakova M. Papillary type 1. website. Accessed January 24th, 2021.
Definition / general
  • Type 1 vs type 2 described in 1997 by Delahunt and Elbe (Mod Pathol 1997;10:537); type 1 is more common than type 2
Essential features
  • Composed of small cuboidal cells with scant pale cytoplasm arranged on single layer of papillary cores, tubules and glomeruloid structures
  • Often contains foamy macrophages and psammoma bodies
  • CK7 diffusely positive (Am J Surg Pathol 2014;38:887)
  • Gains in chromosomes 3, 7 and 17 ( > 80%)
  • MET activating mutations or amplifications (N Engl J Med 2016;374:135)
  • Kidney, renal cortex
  • May be multifocal and bilateral
Diagrams / tables

Images hosted on other servers:

NCCN Clinical Practice Guidelines in Oncology

Clinical features
  • In one series of papillary RCCs, ~25% had classical type 1 features, ~25% were type 2 and ~50% had some degree of overlapping features (Am J Surg Pathol 2014;38:887)
Radiology images

Images hosted on other servers:

Radiological imaging of kidney tumor

Distinct radiology of papillary RCC, type 1

Prognostic factors
Case reports
  • Resection
  • Systemic therapy varies (J Natl Compr Canc Netw 2017;15:804)
    • Receptor tyrosine kinase inhibitors including sunitinib and sorafenib
    • Bevacizumab
    • Nivolumab, cabozantinib and lenvatinib plus everolimus
    • Temsirolimus
Gross description
  • Often well circumscribed with thick capsule
  • Friable with patchy appearance (yellow, grey, brown) and frequent hemorrhage
Microscopic (histologic) description
  • Small cuboidal cells arranged on single layer on papillary cores (Am J Surg Pathol 2014;38:887)
  • Cells are small with uniform, scant pale cytoplasm and round, hyperchromatic nuclei without nucleoli
  • Papillary cores often contain foamy macrophages
  • May have psammoma bodies
  • Lower grade than type 2
  • Grading: ISUP nucleolar grade
Microscopic (histologic) images

Contributed by Nicole K. Andeen, M.D. and Maria Tretiakova, M.D., Ph.D.

Papillary cores filled with foamy macrophages

Type 1 pRCC

Images hosted on other servers:

Small basophilic
tumor cells
(fig. A)

Small basophilic tumor cells and foam cells

Positive stains
Negative stains
Molecular / cytogenetics description
Differential diagnosis
Board review style question #1
Compared to type 2 pRCC, type 1 pRCC generally:

  1. Has more aggressive clinical behavior
  2. Has more CK7 expression and MET activation
  3. Has more diverse chromosomal aberrations
  4. Has more nuclear pleomorphism
Board review style answer #1
B. Has more CK7 expression and MET activation

Reference: Kidney tumor - Type 1 (basophilic) papillary renal cell carcinoma (pRCC)

Comment here
Back to top
Image 01 Image 02