Can basal cells be seen in XXXX ?: an immunohistochemical study using high molecular weight cytokeratin (clone 34betaE12) antibody.

@entity1 @entity263 @entity5 @entity1711 @entity4206 @entity1710 @entity5436
Rare reports describe high molecular weight cytokeratin (clone 34betaE12) antibody cross-reactivity in scattered @entity263 ( @entity263 ) cells, yet most often not in a true basal cell distribution. There are no data specifically describing 34betaE12 reactivity in basal cells in @entity263 . From August 10, 1995 to May 1, 2000, a total of 3198 consult prostate needle biopsies with @entity263 and a 34betaE12 immunoperoxidase stain were reviewed at our institution. Thirty-six cases (1.1%), which on @entity1710 and @entity1711 stain were unequivocal @entity5 , had at least focal 34betaE12 positivity in a basal cell distribution. Twenty-five had original diagnostic slides for review. All @entity5 were Gleason score 6. The mean number of @entity5 glands per case was 36.9 (10-108) with an average of 39% of glands (1-100%) showing 34betaE12 reactivity. Twenty-one cases had patchy staining in a basal cell distribution with one other case showing continuous staining. An additional case showed mainly @entity5 cell reactivity with rare basal cell staining. The final two cases showed a zonal staining pattern with small glands toward one side of the lesion showing basal cells [one with @entity5436 ( @entity5436 ); one without @entity5436 ]. @entity5436 was present in 16 of 25 (64%) cases adjacent to @entity263 . The mean number of @entity5436 glands was 1.36 (1-6). In cases with @entity5436 the mean ratio of @entity263 was 6.8 (0.5-13.0). In 12 cases in which the lesion was still present on deeper sectioning, we were able to confirm in nine cases the presence of basal cells using antibodies to @entity4206 , another marker for prostatic basal cells. Four of the 25 @entity1 underwent radical prostatectomy; all showed Gleason score 6 @entity263 . Three radical prostatectomies demonstrated 34betaE12 reactivity: two with patchy staining in a basal cell distribution and one with mainly @entity5 cell staining. Adjacent @entity5436 was present in all three radical prostatectomy specimens. Rare lesions with the appearance of @entity263 show 34betaE12 staining in a basal cell distribution either from retention of basal cells by early invasive @entity5 or from @entity5436 outpouching. The lack of adjacent @entity5436 in some cases and the large ratio of small atypical glands to @entity5436 glands argue against @entity5436 outpouching as the sole explanation. In cases with adjacent @entity5436 a comparison of the proximity and number of the small, atypical, infiltrative appearing glands to @entity5436 is helpful. The diagnosis of @entity263 in the face of positive 34betaE12 basal cell staining should be made with extreme caution, only in the face of unequivocal @entity5 on the @entity1710 and @entity1711 stain.
