Renal Cell Carcinoma: A Study Of Morphology, Immunophenotype, And Cytogenetic

Renal cell carcinoma (RCC) is a group of heterogenic tumor which is commonly found more than 90% of human kidney malignancies. Different subtypes of RCC have different biological potentials and prognosis. Molecular biologic and cytogenetic researches promote advanced understandings of tumorigenesis and progression of RCC, accompanied with various targeted therapies emerged to different RCC subtypes treatments. Based on the morphology and cytogenetics, WHO 2004 classification subdivides RCC into 10 subtypes. However, there are always some overlaps or similarities of morphology features between different subtypes, which brings the obstacle for a correct classification and diagnosis.Thus, we investigated the classification and differential diagnosis of RCC by three following parts: 1.We summarized clinicopathological features of 343 cases of RCC retrospectively to analyze tumor morphology, grading and staging characters in different subtypes of RCC. 2.We collected RCC and other associated renal tumors with similar papillary architecture in morphology to perform histological, immunophenotypic and cytogenetic studies. 3.We also collected RCC and other associated renal tumors with eosinophilic cytoplasm in morphology to perform histological and immunophenotypic studies. The main results and conclusions are as follows:1. Clinicopathological data: The age of 343 patients of RCC ranged from 12 to 86 years (mean 53.3 years), male is more than female, total sex ratio is 1.7:1. Location ratio is 0.8:1 (left vs. right); the clinical manifestation includes hematuria, lumbar and abdominal pain, abdominal mass, or even discovered by physical examination occasionally. The predominant subtype of RCC, clear cell renal cell carcinoma (CCRCC) in 287 cases (83.7%), papillary renal cell carcinoma (PRCC) in 26 cases (7.6%), chromophobe renal cell carcinoma (CRCC) in 23 cases (6.7%), The RCC prevalence is various and occult.2. Histology: Fuhrman grading and pathological staging: Most of CCRCC is in Fuhrman grade 2, 3; High grade classification is more common in type 2 PRCC. Low grade classification is more common in other types. All subtypes of RCC is predominant in low stage in pathology staging. It is with great challenge in the differential diagnosis of RCC with papillary architecture or eosinophilic tumor cells.3. RCC with papillary architecture is about 16.2% in total RCC. Papillary architecture formation has individual character in every subtypes of RCC. It is very key for differential diagnosis to correctly distinguish primary and secondary papillary.Combined use of CK7,Vimentin,CD10,AMACR,CD117 is with great value in the differential diagnosis of RCC with papillary architecture. Combined use of CK7, CD57,AMACR,WT1 is with great value in the differential diagnosis of PRCC,MA,and NB. The FISH results in 8 unRCC cases suggests that seven of them were morphologically characteristic PRCC, The detection of the 7, 17 chromosome status is necessary for diagnosis of unRCC.4. Combined use of CK7,Vimentin,CD10,AMACR,CD117 is very helpful to the differential diagnosis of RCC with eosinophilic tumor cells.The strongly expression of CD10 in membrane suggested the diagnosis of CCRCC, and diffused expression of CD117 in cytoplasm suggested the diagnosis of CRCC.