UROLOGICAL SURVEY   ( Download pdf )

 

PATHOLOGY

Papillary Renal Cell Carcinoma: Assessment of Clear Cell Change and Clinicopathologic Correlation
Dasgupta CG, Yeh YA
Westchester Medical Center and New York Medical College, Valhalla, NY, USA
Mod Pathol Suppl 1. 2006; 19: 138A

  • Background: Papillary renal cell carcinoma with clear cell change and chromosome 3p21 aberration has been described. The significance of this finding, however, remains unclear. We perform the first study to investigate the significance of clear cell change and its clinicopathologic correlation.
  • Design: Nineteen cases of papillary renal cell carcinoma between 1992 and 2005 were retrieved from the slide archives in the Department of Pathology, Westchester Medical Center. Cytogenetic findings were obtained in 2 cases. All tumors were subclassified as type 1 or 2 and were evaluated for clear cell change and Fuhrman nuclear grade. American Joint Committee on Cancer TNM Staging of Renal Cell Carcinoma (2002) was used and clinical charts were reviewed retrospectively to obtain clinical stage.
  • Results: The patient age ranged from 11 to 77 years (mean 56). Sixteen patients were males and 3 were females. Tumor size ranged from 1.8 to 10 cm (mean 4.6 cm). All tumors contained clear cells ranged from 0 to 85%. Of the 12 tumors with 0 to 25% clear cells, 9 cases presented with stage I, 2 with stage II, and 1 with stage III disease. Seven tumors possessed clear cell change ranged from 30 to 85%. Of these 7 patients, 2 cases presented with stage I, 1 with stage II, 3 with stage III, and 1 with stage IV. Cytogenetics findings in a tumor with 30% clear cells revealed 49-50X,-X, der(3)add(3)(p21),+7,+17,-19,+21 and the case with 5% clear cells showed 57,XXY,+2,+3,+4,+7,+8,+12,+16,+17,+20. Nine cases (47%) were classified as type 1 and 10 cases (53%) type 2. Of the 9 type 1 tumors, 2 cases had grade 1 nuclei, 6 grade 2, and 1 grade 1. Six of these patients presented with stage I, 2 with stage 2, and 1 with stage IV. In comparison to type 1, 5 cases of type 2 lesions had a nuclear grade of 2 and 5 had grade 3 nuclei. Five patients presented with stage I, 1 with stage II, and 4 with stage III disease.
  • Conclusions: Type 2 papillary renal cell carcinomas have higher nuclear grade and stage than that of type 1 lesions. Type 2 lesions have poorer prognosis than type 1. Patients bearing tumors with greater than 30% clear cells present with higher stage of disease. Therefore, clear cell change may be a useful pathologic prognosticator in evaluating clinical behavior of these tumors.

  • Editorial Comment
    Papillary renal cell carcinoma has a tendency to present at a lower stage, but with a distinct potential for progression and aggressive behavior (1). Papillary renal cell carcinomas comprise approximately 10% of renal cell carcinoma in large surgical series. The tumor is characterized by malignant epithelial cells forming varying proportions of papillae and tubules. The tumor papillae contain a delicate fibrovascular core and aggregates of foamy macrophages and cholesterol crystals may be present. Solid variants consist of tubules or short papillae resembling glomeruli.
    Two morphological types of papillary renal cell carcinoma have been described (2). Type 1 tumors have papillae covered by small cells with scanty cytoplasm, arranged in a single layer on the papillary basement membrane. Type 2 tumor cells are often of higher nuclear grade with eosinophilic cytoplasm and pseudostratified nuclei on papillary cores. Type 1 tumors are more frequently multifocal. Sarcomatoid dedifferentiation is seen in approximately 5% of these tumors and has been associated with both type 1 and type 2 tumors. In series of papillary renal cell carcinoma containing both type 1 and 2 tumors, five year survivals for all stages range from 49% to 84% with tumor grade, stage at presentation and the presence of sarcomatoid dedifferentiation being correlated with outcome. Longer survivals have been demonstrated for type 1 when compared with type 2 on both univariate and multivariate analysis that included both tumor stage and grade.
    Uropathologists are aware of the fact that some papillary renal cell carcinomas show clear cell differentiation. Torres-Cabala et al. (3) showed that some of papillary renal cell carcinomas with clear cell differentiation show 3p deletion that is a common finding in conventional clear cell carcinoma. They suggested that this finding might represent an early event in tumor progression to conventional clear cell carcinoma. The study of Dasgupta and Yeh is a further evidence that clear cell differentiation in papillary renal cell carcinomas may have prognostic implications. Patients bearing tumors with greater than 30% clear cells presented with higher stage of disease. Pathologists should report on presence of clear cell differentiation in papillary renal cell carcinomas.

References
1. Amin MB, Corless CL, Renshaw AA, Tickoo SK, Kubus J, Schultz DS: Papillary (chromophil) renal cell carcinoma: histomorphologic characteristics and evaluation of conventional pathologic prognostic parameters in 62 cases. Am J Surg Pathol. 1997; 21: 621-35.
2. Delahunt B, Eble JN: Papillary renal cell carcinoma: a clinicopathologic and immunohistochemical study of 105 tumors. Mod Pathol. 1997; 10: 537-44.
3. Torres-Cabala CA, Wrathall LS, Ronchetti RD, Chian CA, Sobel WM, Linehan WM, Merino MJ: Molecualr and cytogeentic profile of type 1 papillary renal cell carcinoma with clear cell differentiation: Concurrence or tumor progression? Mod Pathol Suppl. 1 2004; 17: 180A.

Dr. Athanase Billis
Full-Professor of Pathology
State University of Campinas, Unicamp
Campinas, Sao Paulo, Brazil