Prostatic intraepithelial neoplasia (PIN)
High grade PIN with adjacent small atypical glands (PINATYP)

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

Revised: 8 August 2016, last major update May 2015

Copyright: (c) 2003-2016,, Inc.

PubMed Search: High grade PIN with adjacent small atypical glands
Cite this page: High grade PIN with adjacent small atypical glands (PINATYP). website. Accessed October 20th, 2018.
Definition / general
  • Defined as high grade PIN (HGPIN) with immediately adjacent focus of small atypical glands (Hum Pathol 2001;32:389)
  • More of a diagnostic dilemma than a pathologic entity
Prognostic factors
Microscopic (histologic) description
  • Several small atypical glands within 0.01-0.4 mm from HGPIN (0.12 mm on average, Hum Pathol 2001;32:389)
  • The cytologic features of these small atypical glands are similar to adjacent HGPIN, i.e. enlarged nuclei, prominent nucleoli and dark amphophilic cytoplasm
  • It is unclear whether these adjacent small atypical glands represent outpouchings, buddings or tangentially sectioned adjacent HGPIN, or represent a focus of associated infiltrating adenocarcinoma
Microscopic (histologic) images

Images hosted on other servers:

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Arrows point to small atypical glands adjacent to larger HGPIN glands

Negative stains
  • Negative staining for high molecular weight cytokeratin (34βE12) has not been helpful in predicting risk of cancer on repeat biopsy
  • In the seminal study of PINATYP, 2 of 8 patients with negative staining had cancer on repeat biopsy, while 2 of 4 patients with positive staining had cancer on repeat biopsy (Hum Pathol 2001;32:389)
Differential diagnosis
  • HGPIN with budding / tangentially sectioned glands: the atypical glands may fuse with the HGPIN on levels, but the absence of fusion should not be taken as evidence supporting a diagnosis of invasive carcinoma
  • Infiltrative carcinoma between HGPIN glands: can be diagnosed if the small infiltrating glands are too numerous or too far away (> 0.4 mm) from the HGPIN glands