American Urological Association - Carcinoma With Squamous Differentiation


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Carcinoma With Squamous Differentiation

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  • Primary carcinoma of prostate with squamous cell features and includes pure squamous cell carcinoma (SCC) and adenosquamous carcinoma (ASC) or adenocarcinoma mixed with squamous cell carcinoma
  • Very rare, only ~55 cases SCC and ~30 cases ASC reported.
  • Diagnosis requires exclusion of secondary prostate SCC from other organs.
  • Both SCC and ASC can arise de novo or preceded by prior prostate adenocarcinoma with or without prior radiation or hormonal treatment.
  • Serum PSA or PSAP typically normal, even with advanced disease.
  • Generally poor response to surgical, hormonal, chemotherapeutic, or radiation therapies.
  • Histology:
    • Pure SCC is similar to SCC of other anatomic sites (e.g. keratin formation, intercellular desmosomes, etc.) (image A) & (image B).
    • Well to poorly differentiated (Broder's grading).
    • Glandular component of ASC similar to acinar adenocarcinoma.
  • By immunohistochemistry:
    • SCC is PSA- and PSAP- and HMWK+.
    • Glandular component of ASC is PSA+ and PAP+ and HMWK-.
  • Do not confuse this with squamous metaplasia adjacent to an infarct (much more common diagnosis).
  • Behave more aggressively than prostate adenocarcinoma.