title: Prostate carcinoma with squamous differentiation: an analysis of 33 cases.
abstract: BACKGROUND
  Only sporadic cases of prostate carcinomas with squamous differentiation have been reported.
  
  
  METHODS
  The files of two institutions were reviewed for prostate cancers with squamous differentiation.
  
  
  RESULTS
  A total of 33 cases were studied. The average age at diagnosis was 68 years (range 49-86 years). The most common presenting symptoms included bladder outlet obstruction and dysuria. Thirteen men had a positive digital rectal examination. Diagnosis was made by needle biopsy (n = 23); transurethral resection of the prostate (n = 5); needle and transurethral resection of the prostate (n = 1); transurethral resection of the bladder (n = 1); or biopsy of metastases (n = 3). In 21 of 33 cases, there was a prior diagnosis of adenocarcinoma of the prostate; 8 patients were treated with hormones, 4 were treated with radiation, and 1 received both radiation and hormone therapy. Of the 12 men without a prior diagnosis of adenocarcinoma, 2 patients had received hormonal therapy for benign prostatic hyperplasia. Eight of 33 cases were pure squamous carcinomas. The remaining cases were adenosquamous carcinoma (n = 16), adenosquamous and urothelial carcinoma (n = 3), and adenosquamous carcinoma and sarcoma (n = 6). The squamous carcinoma component of these mixed cases averaged 40% of the tumor volume (range 5%-95%) and had a range of cytologic atypia (mild [n = 6], moderate [n = 17], severe [n = 10]). In the 25 cases with adenocarcinoma, the glandular component tended to be high-grade (Gleason grade >6 in 19 cases). Immunohistochemistry for prostate specific acid phosphatase and prostate specific antigen was positive in a large percentage of the adenocarcinomas (85% and 75%, respectively) and only very focally positive in 12% of the squamous carcinomas. 34 beta E12 was diffusely positive in >95% of the squamous carcinomas and only focally positive in <10% of the adenocarcinomas. Cytokeratins 7 and 20 did not differentiate the squamous and adenocarcinoma components. Follow-up was available on 25 of 33 cases, with the average survival being 24 months (range 0-63 months).
  
  
  CONCLUSIONS
  Squamous differentiation in prostate cancer is uncommon, often but not necessarily arising in the setting of prior hormone or radiation therapy, and is associated with a poor prognosis. In addition to pure squamous cell carcinoma and adenosquamous cancer, other patterns may be seen. Whereas the adenocarcinoma component is typically high grade, the squamous component has a wide range of differentiation.
authors.affiliation: Department of Pathology, Johns Hopkins Hospital, Baltimore, MD 21231, USA.
authors.forename: Anil V
authors.initials: AV
authors.lastname: Parwani
authors.forename: J D
authors.initials: JD
authors.lastname: Kronz
authors.forename: E M
authors.initials: EM
authors.lastname: Genega
authors.forename: P
authors.initials: P
authors.lastname: Gaudin
authors.forename: S
authors.initials: S
authors.lastname: Chang
authors.forename: J I
authors.initials: JI
authors.lastname: Epstein
mesh_terms: D000135:Acid Phosphatase; D000230:Adenocarcinoma / Q000737:chemistry / Q000401:mortality / Q000556:secondary* / Q000628:therapy; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000401:mortality / Q000556:secondary* / Q000628:therapy; D002471:Cell Transformation, Neoplastic; D003131:Combined Modality Therapy; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D017027:Protein Tyrosine Phosphatases / Q000032:analysis; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D000135:Acid Phosphatase; C428439:prostatic acid phosphatase; D017027:Protein Tyrosine Phosphatases; D017430:Prostate-Specific Antigen