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. Author manuscript; available in PMC: 2019 May 1.
Published in final edited form as: Cancer Cytopathol. 2018 Feb 16;126(5):326–335. doi: 10.1002/cncy.21982

Table 1.

Criteria used to determine differentiation

Well differentiated Poorly differentiated
Excluded by

  • IHC loss of RB

  • RB1 or KRAS mutation

  • Loss of staining for DAXX or ATRX

  • Mutation for DAXX, ATRX, or MEN1

  • G1/G2 on prior pancreas resection or biopsy

  • Ki67 <20% on all tumor samples
Supported by (at least one of the following)

  • G1/G2 on prior pancreas resection or biopsy

  • Adenocarcinoma component

  • Ki67 proliferation rate <20% on all tumor samples

  • Loss of DAXX or ATRX protein expression by immunohistochemistry

  • DAXX, ATRX, or MEN1 mutation

  • 3 cytologists agree well differentiated by morphology

  • Ki67 proliferation rate >20% on all tumor samples

  • Loss of RB protein expression by immunohistochemistry

  • Protein overexpression of p53 by immunohistochemistry

  • RB1, TP53, or KRAS mutation

  • 3 cytologists agree poorly differentiated by morphology