ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 PS-26-058 Plasmacytoid urothelial carcinoma of the bladder: histological and clinical features of 14 cases M.M. Hamzaoui*, A. Zehani, K. Chaker, Y. Ouanes, Y. Nouira, B. Chelly, A. Ayari, O. Belhadj, I. Chelly, H. Azouz, K. Bellil, S. Haouet *Department of Pathology, La Rabta Hospital, Tunis, Tunisia Background & objectives: The plasmacytoid urothelial carcinoma (PUC) of the bladder is a rare and aggressive subtype of urothelial carcinoma (UC) with delayed presentation, infiltrative spread, and poor prognosis. In this study, we report clinicopathological and prognosis outcomes on patients with bladder PUC. Methods: 14 cases with pathologically proven PUC were identified among 566 bladder UC between 2001 and 2021. Archived H&E-stained slides were reviewed for pathologic analysis, including histologic features, tumour grade, association with UC, lymphovascular invasion, metastasis to lymph nodes and other organs, and cancer TNM stage. Clinical data, including age, clinical presentation, treatment, and outcomes were retrieved from patients medical records. Results: 2.47% of invasive UC of the urinary bladder show plas- mocytoid phenotype. Mean age was 68 years. 80% of patients pre- sented with haematuria. All 14 patients underwent cystoprosta- tectomy with urinary diversion. Histologically, all tumours were high grade carcinomas. Pure plasmacytoid features were seen in 4 cases, while in the others 10 cases, the plasmacytoid phenotype was mixed with conventional UC. Lymphovascular invasion and metastasis to lymph nodes were seen in 71.42% and 64.28% of cases respectively. 57.14% Cases were PT2 stage, 28.57% cases were PT3 stage and 14.28% cases were PT4 stage. The 3 year sur- vival rate was ranged from 64.2% without locoregional recurrence to 57.1% without distant recurrence. Conclusion: Accurate identification of UC histological subtypes is an important part of risk stratification,as these variants exhibit malignant biological characteristics. Bladder PUC presents a dis- tinctive clinicopathological outcome represented by high aggres- siveness and poor survival rate. PS-26-059 Prognostic value of keratins and desmosomal proteins in mus- cle-invasive urothelial carcinoma A. Scherping*, C. Garbers, J. Luzha, M. Schostak, B. Jandrig, A. Hartmann, N. Abele, M. Eckstein, P. Ströbel, B. Tomasik, P. Czapiewski *University Hospital Magdeburg, Germany Background & objectives: Keratins (CK) and desmosomal proteins like desmoglein (DSG) and desmocollin (DSC) have diagnostic and prognostic value in many tumour entities. We investigated their prog- nostic value in primary tumour (PT) and matched lymph node metas- tases (LNM) from muscle-invasive bladder cancer (MIBC). Methods: Tissue micro arrays (TMA) were generated for PT and corresponding LNM. Samples were immunohistochemical stained for keratins (CK8, CK18, CK7, CK19, CK20, CK10, CK13, CK5, CK14, CK17) and desmosomal proteins (DSG3, DSC3, DSG2). Evaluation was done using the H-Score and correlation between PT and LMN followed by survival analysis using Cox proportional- hazard model. Results: The study cohort consisted of 232 cases of which 66 cases (28%) had LNM. We noted significant (p<0.05) and positive (r>0,60) correlations in the expression of CK7, CK8, CK19 ,CK20 and CK5 in PT and LMN. In the multivariable Cox regression analysis, we found that CK10 levels in PT were independently associated with worse outcomes – hazard ratio (HR) 1.08 (95% confidence interval [CI]: 1.03-1.13) for overall survival (OS) and HR 1.12 (95%CI:1.05-1.18) for relapse-free survival (RFS). Conclusion: Our results of a two-centre cohort show that the immunohistochemical expressions of CK and desmosomal protein have different concordance in PT and matched LMN in MIBC. While the simple and luminal proteins, respectively, tend to show correlative expression, basal proteins like CK10, DSG3, DSC3 (except CK5) had no or little correlation in their expression pat- tern of PT and LMN. A high CK10 expression in PT is significantly associated with worse outcomes, both RFS and OS. Funding: Doctoral Scholarship University Hospital Magdeburg PS-26-060 SHH pathway tissue expression depends on histological type of germ cell tumours K. Czarnota, B. Lipska-Zietkiewicz, W. Grajkowska, J. Stefano- wicz, E. Drozynska, B. Dembowska-Baginska, M. Jankowski, A. Jasiak, K. Buczkowski, E. Izycka-Swieszewska* *Medical University of Gdansk, Copernicus Hospital, Gdansk, Poland Background & objectives: Sonic hedgehog (SHH) pathway affects embryological cell migration, morphogenesis, gonadal formation, and sexual differentiation. SHH signalling is activated in many aspects of cancerogenesis, including the biology of paediatric germ cell tumours (GCTs)- a heterogeneous group of neoplasms. Methods: 98 GCTs (46 girls, 52 boys; 1m-18yrs) examined: 7 embryonal carcinomas (EC), 19 seminomatous tumours (SEM), 18 yolk sac tumours (YOL), 33 immature teratomas, 6 mature teratomas, 15 mixed-type tumours. The clinical presentation, tumour localization, stage varied. SHH pathway elements: SHH, PTCH-1, SMO, SUFU, GLI-1, GLI-2, GLI-3 were evaluated immunohistochemically on FFPE sections (TMAs, full sections) with own semi-quantitative scale. Results: In immunohistochemical analysis EC, SEM, YOL tumours (homogenous cases and components of mixed tumours) were strongly positive for GLI-1 (nuclear), SHH (membranous and cytoplasmic), and PTCH-1 (nuclear). In parallel, GLI-2 (nuclear) and SUFU (nuclear) were varied in expression, while GLI-3 (nuclear) and SMO (cytoplas- mic and nuclear) were mostly negative/ weak. Protein expression in teratomas was variable in intensity and localization, dependent on con- stituent tissue type, with heterogeneous presentation between tumours and even individual slides. Primitive neuroectoderm revealed high SHH expression. The stroma of GCTs was also positive for pathway proteins in the majority of cases, although rarely showed full concordance to the staining of tumour cells. Conclusion: GCTs show heterogeneous SHH pathway proteins tis- sue expression, related to their histological type. SHH expression in tumour cells and tumour stroma suggests its auto- and paracrine role in their biology. No significant difference was found between protein expression in monomorphic tumours and corresponding components in mixed tumours. Funding: Polish National Science Centre Grant NCN 2014/15/B/ NZ4/04855 (leader—E. Izycka-Swieszewska PS-26-061 TFE3 is related with PI3K/Akt pathway in renal cell carcinoma H.J. Lee* *Pusan National University, Department of Pathology, Yangsan, Republic of Korea S184