Objective: Renal cell carcinomas (RCC) is the seventh most common human malignancy. RCC is now recognized to be a complex neoplasm consisting of several different tumor subtypes, each with distinct genetic and clinical features. The aim of this study was to investigate the expressions of cyclooxygenase-2 (COX-2), P53 and CD95 in RCC that has different clinicopathologic characteristics. Method: This study was conducted on a total of 49 paraffin embedded kidney samples (tumoral samples), which were histopathologically diagnosed at department of pathology from 2005 to 2011. IHC stains for COX-2, P53 and CD95 were performed on tissue microarray using standard procedures. Results: There were significant correlations between COX-2 and subtype (p=0,044), COX-2 and diameter (p=0,026). Significant relationships were found between p53 and age (p=0,050), P53 and diameter (p=0.050). Besides, there were significant correlations between CD95 and furhman grade (p=0,050). Conclusion: CD95, COX-2, P53 expression correlates with prognostic parameters in the RCC patients. In addition, COX-2, P53, CD95 expression in RCC may be associated with tumor progression. Objective: EBV related malignancies (skin cancers, lymphomas, Kaposi sarcomas) complicates organ transplantation EBV-associated smooth-muscle tumors are rare. Method: Among 1500 kidney grafted patients, three developed EBV-SMT. Case 1. Female 51 y, with EBV-SMT (Generalized) Case 2. Female 46 y, breast phylodes sarcoma, reviewed diagnosis: EBV-SMT. Case 3. Male 23 year, severe abdominal pain, 2 gut tumor-like nodules were excised suspection of TBC. EBV-SMT was microscopic diagnosis. Results: Progressive weight-loss all 3patients, chronic cough in patient 1, chest X ray multiple pulmonary lesions, on CT-scan paravertebral lesions. Transthoracic biopsy: spindle cells proliferation with mixed cellularity eosinophilic cells intermingled fascicles resembling smooth muscle, mononuclear inflamatory cells and capillarie evoqued myofibroblastic tumor. No mitosis, mild nuclear atypia. Negative immunohistochemestry: CD21, CD34, CD99, EMA, cytokeratin, S100, CD117. Alpha-smooth muscle actin diffusely positive, EVB-LMP negative. In situ hybridization : EBV + nuclei. EBV-SMT was established. Conclusion: SMT in immunocompromised are EBV associated. Primary target of EBV are B lymphocytes, may infect smooth-muscle through receptor for EBV CD21 Mechanisms of EBV related-tumor genesis is integration of EBV-DNA within ALK locus in tumor cells. ALKgene rearrangement and expression; associated with inflammatory myofibroblastic tumors, anaplastic large-cell lymphomas etc. Clonally of multifocal EBV-SMT using southern blot showed, multiple tumors constitute independent primary lesions. Method: The degree of glomerulosclerosis was scored into 0-3, mesangial proliferation was scored into 0 (absent) and 1 (present), and the degree of crescents was scored into 0-2. Glomerular injury score (GIS) was obtained by adding the above 3 scores and grouped into 3 categories (group 1, score 0-1; group 2, 2-4; group 3, 5-7). Results: Serum creatinine level was significantly increased (1.3±0.4, 1.8±0.9, 2.2±0.8 mg/dL, p=0.007), estimated glomerular filtration rate (eGFR) was significantly decreased (68.5±17.6, 52.1±22.5, 40 .9±20.4 mL/min, p= 0.001) and proteinuria was significantly increased as GIS increased (1.3±2.7, 1.9±1.6, 4.6±7.1 g/24 h, p=0.030). Interstitial fibrosis of more than 25 % of cortical area increased as GIS increased (2.3, 26.0, and 57.1 %, p<0.001). When a multivarate analysis was done, GIS group 3 was the most important predictive factor of eGFR (p=0.009) and proteinuria (p=0.014). Objective: The aim of the study is to evaluate the histopathological finding and the C4d staining patterns of the patients who were biopsied due to graft dysfunction (GD) after initial well-function within 1 month of deceased donor kidney transplantation (DDKT). Method: Histological analysis and C4d immunostaining were performed 34 on needle core biopsies. Results: Thirty-four patients (mean age: 37±8 years, male: 59 %) were included. Histological analysis revealed acute rejection (AR) (n:7), acute tubular injury (ATI) (n:8), allograft infection (n:1), borderline changes (n:8), normal morphology (n:3), and donor-related changes (n:7). C4d staining was detected in 44 % (15 of 34) biopsies; staining patterns were diffuse (n:5), focal (n:5) and minimal (n:5). Diffuse (n:3) and focal (n:1) C4d positivity accompanied 4 of 7 cases of AR. In remaining 27 patients having non-AR histological picture, diffuse or focal C4d positivity were detected in 2 and 4 cases, respectively. Peritubular capillaritis was detected in 41.1 % (14/34) of biopsies, of which four had C4d diffuse, one had C4d focal positive. Conclusion: Beyond cold ischemia time-induced ATI, immunological causes including antibody mediated process may play an important role in early impairment of graft function after DDKT.