• All IHC stains will include a positive control tissue

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.

Note:

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).

Submit a formalin-fixed, paraffin embedded tissue block

Formalin-fixed, paraffin embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• 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

References

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.