Allina Health Laboratory a part of Abbott Northwestern Hospital



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Test Name:Prostatic acid phosphatase by IHC
Test Number:12376 - Technical only; 12379 - Technical & Interpretation
Collect:Formalin-fixed, paraffin embedded (FFPE) tissue block
Container:FFPE tissue block
Processing:Submit processed tissue block or tissue section mounted on a charged, unstained slide
Transport/Stability:Ambient (preferred)
Alternate Names:PSAP
Performing Lab:AHL - Immunohistochemistry
Days Set Up:Mo - Fr
Expected TAT:1 - 2 days
Ref. Ranges:If requested, an interpretive report will be provided
All IHC stains will include a positive control tissue
Processing Details:

  • Monoclonal antibody directed against prostatic acid phosphatase
Staining pattern:
  • Cytoplasmic based staining; prostatic acinar and ductal epithelium reactivity tends to concentrate in the apical portion. Reactivity is also present in prostatic secretions and on the surface of corpora amylacea
  • PSAP is fairly specific for prostate tissue
  • Immunoreactivity for PSAP (and PSA) is generally more intense and homogeneous in benign prostate tissue than in prostatic carcinoma. Occasional cases of prostatic squamous metaplasia may show focal reactivity
  • Other normal/non-neoplastic tissues with reported PSAP reactivity:
    - periurethral glands*
    - anal glands (male only)*
    - urachal remnants*
    - renal tubules
    - neutrophils (cross reactivity with leukocyte acid phosphatase)
    - pancreatic islet cells
    - neuroendocrine cells in clonic crypts
    - seminal vesicle**
    - cystitis cystica and glandularis*
    - (rare reports of focal PSAP reactivity in hepatocytes, breast ducts, and gastric parietal cells)
  • Other neoplasms with reported PSAP reactivity:
    - pure adenocarcinoma of the bladder*
    - periurethral gland carcinomas*
    - gastrointestinal carcinoids (approx. 70% of rectal carcinoids; the frequency of PAP positivity decreases as one ascends the gastrointestinal tract)
    - pancreatic islet cell tumors
    - (rare reports of PSAP reactivity in renal cell carcinoma and breast carcinoma)
  • In general, any cloacal derived tissue may show reactivity with PSAP
  • Normal and neoplastic transitional epithelium is negative
  • Carcinoids found within the ovary, kidney, breast, liver, and head and neck have been PSAP negative

    *both PSAP and PSA reactivity are reported
    **reported for antibodies developed against seminal fluid.


    PSAP monoclonal antibodies have shown a lower sensitivity compared to polyclonal antiserum (In two studies of poorly differentiated prostate carcinoma, monoclonal antibodies stained 59% and 60% of cases whereas polyclonal antibodies stained 83% and 86% of cases).

    1. Epstein JI. PSA and PSAP as immunohistochemical markers in prostate cancer. Urologic Clinics of North America 1993; 20(4):757-70.
    2. Ro JY, et al. Small cell carcinoma of the prostate: immunohistochemical and electron microscopic study of 18 cases. Cancer 1987; 59:977-82.
    3. Azumi. Prostatic acid phosphatase in carcinoid tumors. Am J Surg. Pathol 15(8):785-790, 1991. /ol>
Method:Immunohistochemical staining
Microscopic examination
CPT Codes:88342 - 1st stain
88341 - each additional stain
Date Created:08/08/2017
Revised Date:10/19/2018