Kidney tumor

Adult renal cell carcinoma - common

Papillary type 1

Last author update: 1 October 2017
Last staff update: 7 August 2023 (update in progress)

Copyright: 2003-2023,, 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 2022: 15,465
Page views in 2023 to date: 14,608
Cite this page: Andeen NK, Tretiakova M. Papillary type 1. website. Accessed September 30th, 2023.
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
Frozen section images

Contributed by Debra L. Zynger, M.D.

Delicate papillary cores

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

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Small basophilic
tumor cells
(fig. A)

Small basophilic tumor cells and foam cells

Cytology images

Contributed by Debra L. Zynger, M.D.

Papillary structures and foamy histiocytes

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

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