2007 Winter Meeting - London - The Pathological Society of Great ...

P29Utility of Polyclonal anti-PSA and 34betaE12 ImmunostainingFor Differentiating Prostatic Carcinoma from UrothelialCarcinoma{P} M Varma, B Jasani, PN Mathews, SN Datta, MB Amin1 University Hospital of Wales, Cardiff, United Kingdom, 2 EmoryUniversity, Atlanta, United StatesPSA and 34βE12 immunohistochemistry has been shown to be useful fordifferentiating high-grade prostatic adenocarcinoma (Pca) from Urothelialcarcinoma (Uca). Polyclonal antibody to PSA (pPSA) has been reported to bemore sensitive than monoclonal anti-PSA in high-grade PCa.However, published studies examined only morphologically unequivocalcases. We retrospectively evaluated the utility of pPSA and 34βE12immunostaining in 16 cases that had been signed out as “poorly differentiatedcarcinoma: ?PCa,?Uca” after immunostaining with monoclonal antibodies toPSA, PSAP and/or CEA.Using pPSA and 34βE12, a definite diagnosis could be established in 15(93.8%) of the 16 originally equivocal cases [9 Pca (pPSA+, 34βE12 -), 6 Uca(pPSA-, 34βE12 +)]. In 2 of these cases the possibility of synchronous PCa andUCa had originally been considered in view of patchy immunoreactivity withmonoclonal anti-PSA, but pPSA showed diffuse positivity establishing adiagnosis of PCa. The remaining case was negative for pPSA and 34βE12, andan extended immunohistochemical panel was also non-diagnostic. Clinicalfindings in this case favored UCa but no follow-up was available.Our findings confirm the clinical utility of a simple immunohistochemicalpanel composed of pPSA and 34βE12 for differentiating high-grade Pca fromUca.P30Microwave Pre-treatment Improves the Sensitivity of34betaE12 as a Marker for High-grade Urothelial Carcinoma{P} M Varma, S Wozniak, B JasaniUniversity Hospital of Wales, Cardiff, United KingdomHistopathologic distinction between high-grade urothelial carcinoma (HG-UCa)and prostate adenocarcinoma is critical for appropriate therapy.High molecular weight cytokeratin monoclonal antibody, 34βE12 has beenshown to be a sensitive marker for HG-UCa. A recent study found thesensitivity of 34βE12 immunostaining in HG-UC to be significantly greaterwith the use of microwave heat retrieval, as compared to enzyme predigestion.We describe two cases (1 TURP, 1 prostate needle biopsy) in which the lowersensitivity of 34βE12 immunoreactivity after enzyme predigestion resulted indiagnostic difficulty. In both cases, the poorly differentiated carcinoma wasnegative for PSA and with 34βE12 used after enzyme predigestion at outsideinstitutions and the overall appearances were considered most in keeping withprostate cancer.On repeat immunostaining in our department, in both cases the tumour cellswere negative for PSA and PSAP but diffusely and intensely positive on34βE12 immunostaining performed after microwave pretreatment. Based on themorphology and immunoprofile, a diagnosis of HG-UCa was made on bothcases. This diagnosis was confirmed following cystoprostatectomy in one case,no relevant follow-up is available to date on the other case.We conclude that heat retrieval is the pre-treatment of choice when 34βE12immunostaining is performed to confirm a diagnosis of urothelial carcinoma.P31An Evaluation of the Clinical Utility of Pelvic Lymph NodeFrozen Section Examination Prior to Radical Prostatectomy{P} LJ Aitken, H Kynaston, DFR Griffiths, M VarmaUniversity Hospital of Wales, Cardiff, United KingdomIn the current era of PSA screening, prostate cancer deposits within pelviclymph nodes of patients considered for radical prostatectomy are generallysmall and the utility of frozen section (F/S) examination of these lymph nodesprior to radical prostatectomy is uncertain.In our institution, 101 pelvic lymph node F/S examinations prior to plannedradical prostatectomy were performed between 1996 and 2005. The lymphnodes were partially submitted for F/S examination and entirely submitted afterfixation for definitive histology.Metastatic tumour was found in only 2 (2%) of the cases while there were 3false negative cases. The remaining 96 cases were negative on F/S anddefinitive histology.Review of the 3 false negative cases confirmed the absence of metastatictumour in the cryostat sections. Tumour deposits were found only in paraffinsections from deeper levels of cryostat blocks in two cases and only inadditional blocks submitted after fixation in the third case. Thus, two of thethree false negative cases would have been missed even if the nodes had beensubmitted in total for F/S examination.We conclude that pelvic lymph node frozen section examination prior toradical prostatectomy is not cost effective.P32Bone Marrow-Derived Renal Parenchymal Cells RespondPoorly to the Renotropic Actions of Epidermal Growth FactorT-H Yen 3 , MR Alison 2 , RA Goodlad 1 , WR Otto 1 ,HT Cook 5 ,NA Wright 1 , {P} R Poulsom 11 Cancer Research UK - London Research Institute, London, UnitedKingdom, 2 Queen Mary’s School of Medicine and Dentistry, London,United Kingdom, 3 Chang Gung Memorial Hospital, Taipei, Taiwan,4 Chang Gung University, Taoyuan, Taiwan, 5 Imperial College, London,United KingdomA small percentage of regenerating epithelial cells are derived from bonemarrow (BM) cells following different types of renal injury. We reportedpreviously that these enter S-phase of the cell cycle to assist regeneration, butwe are concerned that they may not respond normally to growth controls, andbe undesirable rather than useful for organ regeneration.We tested whether BM-derived epithelial cells respond to epidermal growthfactor (EGF) in lethally irradiated female mice transplanted with male wholeBM cells. Six-weeks later they received pegylated colony stimulating factor (p-GCSF), EGF, and HgCl 2 singly or in combination, and were killed after 4 days,with tritiated thymidine given one hour earlier to label cells in S-phase.Tubular injury scores and serum urea nitrogen levels were high after HgCl 2injection and reached uremia, but EGF protected from such extreme damage.To explore the cell origin underlying this rescue, kidney sections weresubjected to a “four-in-one” analytical technique for identification of cell origin,tubular phenotype, tubular basement membrane and S-phase status.Transplanted BM contributed ~ 1% of proximal tubular epithelium inundamaged kidneys, ~ 3% in HgCl 2-damaged kidneys, but without furtherincrease after either EGF or p-GCSF injection. Only ~ 0.5% proximal tubularcells were in S-phase without damage, increasing to ~ 7-8% after HgCl 2,and to~ 15% for EGF+HgCl 2 mice. BM contributed ~ 1 in 15 of the S-phaseproximal tubular cells after HgCl 2, but only ~ 1 in 30 after EGF+ HgCl 2treatment.Thus, BM-derived tubular cells are compromised in their ability to respond toa normal renal growth factor, and thus have a selective disadvantage that mightcause them to be lost.Winter Meeting (191 st ) 3–5 January 2007 Scientific Programme35