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atypical small acinar proliferation

Wednesday 30 August 2017

atypical glands in prostate biopsy


Atypical small acinar proliferation (ASAP) occurs in approximately 5% of prostate biopsies.

Approximately 30-40% of patients with ASAP may develop prostate cancer (PCa) within a 5-year period.

Current guidelines recommend a repeat biopsy within 3-6 months after the initial diagnosis.



- example : (ASAP), suspicious for but not diagnostic of malignancy; Focal Glandular Atypia (FGA) and Atypical glands suspicious for cancer

Webpathology : The phrase "atypical glands suspicious for but not diagnostic of cancer" is used when a focus of atypical glands does not have the full complement of cytologic and architectural features for an unequivocal diagnosis of malignancy.

It can be a small focus of 3-5 glands with enlarged nuclei and a few prominent nucleoli.

Higher magnification of the previous image can show nuclear details and intraluminal eosinophilic crystalloids.

The phrase "atypical glands suspicious for but not diagnostic of malignancy (also known as "atypical small acinar proliferation" ASAP) is not a distinct pathologic diagnosis but rather an expression of diagnostic uncertainty applied in a variety of situations including:
- partially sampled focus of cancer,
- atypical glands at the edge of a core,
- artifacts introduced by poor histology (poor fixation, thick sections, suboptimal staining),
- atypical glands adjacent to high-grade PIN,
- atypical glands adjacent to inflammation,
- benign mimics of cancer with atypical features.

Open references

Atypical Small Acinar Proliferation: Repeat Biopsy and Detection of High Grade Prostate Cancer.
Leone A, Rotker K, Butler C, Mega A, Li J, Amin A, Schiff SF, Pareek G, Golijanin D, Renzulli JF 2nd.
Prostate Cancer. 2015;2015:810159. doi : 10.1155/2015/810159
PMID: 26451257 Free

Paywall references

Prostate cancer detection following diagnosis of atypical small acinar proliferation.
Ericson KJ, Wenger HC, Rosen AM, Kiriluk KJ, Gerber GS, Paner GP, Eggener SE.
Can J Urol. 2017 Apr;24(2):8714-8720.
PMID: 28436357

Atypical small acinar proliferation (ASAP): Is a repeat biopsy necessary ASAP? A multi-institutional review.
Leone A, Gershman B, Rotker K, Butler C, Fantasia J, Miller A, Afiadata A, Amin A, Zhou A, Jiang Z, Sebo T, Mega A, Schiff S, Pareek G, Golijanin D, Yates J, Karnes RJ, Renzulli J.
Prostate Cancer Prostatic Dis. 2016 Mar;19(1):68-71. doi : 10.1038/pcan.2015.52
PMID: 26857145