Prostatic intraepithelial neoplasia (PIN)
High grade PIN - Cribriform pattern

Author: Nicholas Reder, M.D. (see Authors page)
Editor: Maria Tretiakova, M.D.

Revised: 1 October 2015, last major update October 2015

Copyright: (c) 2003-2015,, Inc.

PubMed Search: Prostatic intraepithelial neoplasia [title] cribiform
Cite this page: High grade PIN - Cribriform pattern. website. Accessed March 20th, 2018.
Definition / general
  • One of the four dominant patterns of HGPIN along with tufting, micropapillary and flat (Hum Pathol 1993;24:298)
  • The cribriform pattern is least common in its pure form, but is often seen along with the other major patterns
  • Has a broad differential diagnosis including both benign and malignant entities
  • Terminology
  • Synonymous term: isolated atypical cribriform lesion (Am J Surg Pathol 2010;34:470)
  • Microscopic (histologic) description
  • Small (< 1 mm) intraluminal proliferation involving less than 3 glands
  • Characterized by simple architecture, round contours and irregular slit-like spaces
  • Intact or partially retained (discontinuous) basal cell layer
  • Nuclei are atypical, but monotonous, with a low mitotic rate
  • Microscopic (histologic) images
    Missing Image

    Courtesy of Dr. Nicholas Reder

    Missing Image

    Large glandular units

    Missing Image

    Roman bridges

    Missing Image

    Nuclei show enlargement

    Missing Image


    Positive stains
  • Positive staining for high molecular weight cytokeratin (34βE12) or p63 can be helpful in distinguishing cribriform HGPIN from cribriform Gleason pattern 4 adenocarcinoma
  • However, basal cell staining can be patchy or absent in HGPIN, thus a negative stain is essentially non-contributory
  • Negative stains
  • ERG immunostaining is absent in cribriform PIN, but often present in intraductal carcinoma (Mod Pathol 2013;26:587)
  • Differential diagnosis
  • Basal cell hyperplasia:
    • Glands are small, crowded in back-to-back arrangement, and with round to elongated palisading nuclei
    • A high molecular weight cytokeratin stain can be useful in difficult cases
  • Benign central zone glands:
    • Roman bridge formation can be present, but the nuclei often stream parallel; no nuclear atypia
  • Carcinoma, cribriform Gleason pattern 4:
    • The primary difference is a lack of basal cells
    • In addition, carcinoma has greater nuclear atypia and the cribriform pattern is often more round punched-out spaces rather than irregular slit-like seen in HGPIN
  • Clear cell cribriform hyperplasia:
    • Clear cytoplasm, lack of nuclear atypia, prominent basal layer
  • Intraductal carcinoma:
    • Larger (> 1mm, > 6 glands), often has central necrosis, marked nuclear pleomorphism, nucleomegaly (6x of the adjacent benign nuclei) and high mitotic rate
    • Usually associated with infiltrative high grade carcinoma