Sarcomatoid differentiation may be seen in many types of renal carcinomas
(de Peralta-Venturina; Cheville)
It no longer refers to a type of carcinoma
It is considered an adverse prognostic factor
Prognosis may be worse than simple grade 4 carcinoma
Defined as a spindle cell component measuring at least one low power (40x) field with either
Adjacent carcinoma, or
Evidence of epithelial differentiation in the spindle cells
Spindle cells usually show moderate to marked atypia
Frequent patterns include fibrosarcoma, malignant fibrous histiocytoma, rhabdomyosarcoma
Occasional cases have low grade atypia in spindle component
No clinical significance to type of differentation or degree of atypia
May arise in setting of many types of carcinoma
Clear cell RCC (reported 5-8% incidence of sarcomatoid foci, in our experience it is less frequent)
Papillary RCC (2-3% incidence)
Chromophobe RCC (9% incidence)
Collecting duct carcinoma (39% incidence)
Bibliography (for Grading)
Murphy WM, Grignon DJ, Perlman EJ. Tumors of the Kidney, Bladder and Related Urinary Structures, Atlas of Tumor Pathology, AFIP Fourth Series, Fascicle 1, 2004
Delahunt B. Advances and controversies in grading and staging of renal cell carcinoma. Mod Pathol. 2009 Jun;22 Suppl 2:S24-36.
Delahunt B, Sika-Paotonu D, Bethwaite PB, William Jordan T, Magi-Galluzzi C, Zhou M, Samaratunga H, Srigley JR. Grading of clear cell renal cell carcinoma should be based on nucleolar prominence. Am J Surg Pathol. 2011 Aug;35(8):1134-9.
Delahunt B, Bethwaite PB, Nacey JN. Outcome prediction for renal cell carcinoma: evaluation of prognostic factors for tumours divided according to histological subtype. Pathology. 2007 Oct;39(5):459-65.
Lohse CM, Blute ML, Zincke H, Weaver AL, Cheville JC. Comparison of standardized and nonstandardized nuclear grade of renal cell carcinoma to predict outcome among 2,042 patients. Am J Clin Pathol. 2002 Dec;118(6):877-86.
de Peralta-Venturina M, Moch H, Amin M, Tamboli P, Hailemariam S, Mihatsch M, Javidan J, Stricker H, Ro JY, Amin MB. Sarcomatoid differentiation in renal cell carcinoma: a study of 101 cases. Am J Surg Pathol. 2001 Mar;25(3):275-84.
Cheville JC, Lohse CM, Zincke H, Weaver AL, Leibovich BC, Frank I, Blute ML. Sarcomatoid renal cell carcinoma: an examination of underlying histologic subtype and an analysis of associations with patient outcome. Am J Surg Pathol. 2004 Apr;28(4):435-41.
Sika-Paotonu D, Bethwaite PB, McCredie MR, William Jordan T, Delahunt B. Nucleolar grade but not Fuhrman grade is applicable to papillary renal cell carcinoma. Am J Surg Pathol. 2006 Sep;30(9):1091-6.
Delahunt B, Sika-Paotonu D, Bethwaite PB, McCredie MR, Martignoni G, Eble JN, Jordan TW. Fuhrman grading is not appropriate for chromophobe renal cell carcinoma. Am J Surg Pathol. 2007 Jun;31(6):957-60..
Paner GP, Amin MB, Alvarado-Cabrero I, Young AN, Stricker HJ, Moch H, Lyles RH. A novel tumor grading scheme for chromophobe renal cell carcinoma: prognostic utility and comparison with Fuhrman nuclear grade. Am J Surg Pathol. 2010 Sep;34(9):1233-40.
Fuhrman SA, Lasky LC, Limas C. Prognostic significance of morphologic parameters in renal cell carcinoma. Am J Surg Pathol. 1982 Oct;6(7):655-63.
