Clinicopathologic Study Of Renal Epithelial Neoplasms

Objective: To study histological classification, morphology, immunohistochemistry, differential diagnosis and prognosis of renal epithelial neoplasms. Methods: 182 cases of renal epithelial neoplasms and 15 metastatic renal cell cancer retrieved from archived file of the department of pathology of Nanjing General Hospital between 1990 and 2005 were studied for new histological classification guided by the "Tumors of the Urinary System and Male Genital Organs" published in 2004, Fuhrman's nuclear grade and 1997/UICC/AJCC TNM stage. Immunohistochemical analysis of EMA, Vimentin, CD10, CK7, CD117, P504s, Ksp-cadherin, TFE3 were performed on each subtype. Follow-up information was obtained.The relations were analyzed by using x~2 test and the survival rates were assessed by Kaplan-Meier analysis and the survival curves compared by Log-rank test. The multivariate analysis was conducted by Cox model.Results: (1) CCRCC was comprised of solid, alveolar, acinar pattern with clear or eosinophilic cell. PRCC was characterized by malignant epithelial cells forming varying proportions of papillae and tubules.The tumour papillae contain a delicate fibrovascular core and aggregates of foamy macrophages and cholesterol crystals may be present. ChRCC was comprised of sheet, trabecular and alveolar architecture. The tumors composed of chromophobe cells and eosinophilic cells. Chromophobe cells which have distinct membranes are larger and polygonal with translucent and finely reticulated cytoplasm.Eosinophilic cells have eosinophilic cytoplasm and perinuclear halo. Wrinkled, grooved and bizarre nuclei can be found in ChRCC and nucleoli are not obvious. Oncocytoma has solid compact nests. Often there is a hypocellularhyalinized stroma. The predominant cell type is round-to-polygonal with densely granular eosinophilic cytoplasm, round and regular nuclei with a centrally placed nucleolus. RCC associated with Xp11.2 translocations/TFE3 gene fusions revealed two pattens in all cases. One patten consisted of alveolar, papillary or nested architecture and cells with voluminous, clear to eosinophilic cytoplasm, distinct cell borders, vesicular chromatin, and prominent nucleoli. Psammoma bodies are frequently found in tumors and sometimes extensively distributed. Another one constituted a more nested and compact architecture and cells with less abundant cytoplasm. Fewer psammoma bodies were detected. MTSCC was composed of tightly packed, small, elongated tubules separated by pale mucinous stroma. The parallel tubular arrays often have a spindle cell configuration. CCDB has irregular tubules, nests with high-grade nuclei extensively infiltrating in a desmoplastic stroma. (2)CD10 expression was mainly seen in CCRCC, PRCC, Xp11 RCC and metastatic renal cell cancer. CD10 was also expressed in ChRCC in cytoplasmic pattern, compared with membranous staining in the other tumors.Vimentin expressed in CCRCC, PRCC, MTSCC and metastatic renal cell cancer. CK7 mainly expressed in ChRCC and PRCC. EMA highly expressed in CCRCC, PRCC, ChRCC, Oncocytoma and metastatic renal cell cancer. High expression of P504s was noted in CCRCC, PRCC, Xp11 RCC, MTSCC and metastatic renal cell cancer. TFE3 only expressed in Xp11 RCC. Ksp-Cadherin and CD117 mainly expressed in ChRCC and oncocytoma. On the other hand, the expression of Ksp-Cadherin in CCRCC correlated with tumor stage and grade. (3) Kaplan-Meier analysis showed that unfavorable variables for survival rate of CCRCCwere high stage (Pt3/Pt4), high grade (G3/G4) and expression of Ksp-Cadherin. (P<0.01) but only the stage and expression of Ksp-Cadherin entered the Cox regression model.Conclusions :(1) Renal epithelial neoplasms are a group of distinctive and heterogeneous entities in morphology. Diagnosis can be made by gross and microscopic examination. (2)The different histologic subtypes of kidney tumor and metastatic renal cell cancer have unique immunophenotyppes. Immunohistochemical staining is useful in differential diagnosis, when a diagnostic challenge presents on routine staining. CD10, Vimentin , CK7, CD117 , EMA, P504s, Ksp-cadherin and TFE3 is a helpful panel in the histologic categorization. (3) The clinical outcomes of the various histologic subtypes are different. (4) 1997 UICC/AJCC/TNM stage and expression of Ksp-Cadherin are independent prognostic predictor of CCRCC.