Keratin and EMA should be negative unless appropriate for type of sarcoma
Specific sarcoma type markers such as desmin for leiomyosarcoma may be useful
Sarcomatoid urothelial carcinoma
Identification of location and type of associated carcinoma are important
History of prior urothelial tract carcinoma is helpful
High molecular weight keratin and p63 staining would support urothelial carcinoma although published evidence is scant
Angiomyolipoma
Generally only a problem if smooth muscle component predominates
Smooth muscle differentiation is unusual in sarcomatoid RCC
HMB45 staining would not be expected in sarcomatoid RCC (but no published evidence)
Identification of associated typical angiomyolipoma or RCC is important
Grading / Staging
Grading
Presence of sarcomatoid differentiation indicates high grade
Grade of sarcoma is not relevant
Staging
Use TNM staging for all renal carcinomas at present
Remember that it is based predominantly on clear cell carcinomas
It has not been validated as applicable to other types of carcinoma (see Herrmann for an example)
Critical/controversial points in staging of RCC include:
pT3a is defined as extension into perirenal fat
This requires actual infiltration into and between fat cells
It does not include bulging tumor with stretched, thin capsule that appears to touch fat
Classically has been considered fat peripheral to the cortical capsule
It appears that renal sinus (peripelvic) fat should be considered equivalent
The renal sinus must be examined grossly and appropriately sampled
pT3 requires gross involvement of renal vein and or vena cava
This requires an adequate gross examination
Retraction of vascular wall around a lumenal tumor thrombus may falsely suggest a positive margin
Positive vascular margin requires involvement of the vessel wall at the margin
Direct (contiguous) invasion of the adrenal gland (pT4) should be distinguished from discontiguous (metastatic) involvement (pM1)
Bibliography (for Staging)
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.
Bonsib SM. The renal sinus is the principal invasive pathway: a prospective study of 100 renal cell carcinomas. Am J Surg Pathol. 2004 Dec;28(12):1594-600.
Bonsib SM. Renal veins and venous extension in clear cell renal cell carcinoma. Mod Pathol. 2007 Jan;20(1):44-53.
Bonsib SM. T2 clear cell renal cell carcinoma is a rare entity: a study of 120 clear cell renal cell carcinomas. J Urol. 2005 Oct;174(4 Pt 1):1199-202; discussion 1202.
Herrmann E, Trojan L, Becker F, Wülfing C, Schrader AJ, Barth P, Stöckle M, Hammerschmied CG, Staehler M, Stief C, Haferkamp A, Hohenfellner M, Legal W, Wullich B, Bolenz C, Klein T, Noldus J, Bierer S, Hertle L, Brenner W, Roos F, Michel MS, Walter B, Wieland W, Gerss J, Otto W, Hartmann A. Prognostic factors of papillary renal cell carcinoma: results from a multi-institutional series after pathological review. J Urol. 2010 Feb;183(2):460-6.
Clinical
Wide age range 29-81 years
Poor prognosis
22% 5 year survival
Clinically significant features
Percentage of sarcomatoid pattern (>50%)
Vascular invasion
Degree of necrosis
High TNM stage
Type and grade of sarcoma and type of carcinoma is not clinically significant
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
Eble JN, Sauter G, Epstein JI, Sesterhenn IA eds. World Health Organization Classification of Tumors. Pathology and genetics of tumors of the Urinary System and Male Genital Organs. IARC Press: Lyon 2004.
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.
Delahunt B. Sarcomatoid renal carcinoma: the final common dedifferentiation pathway of renal epithelial malignancies. Pathology. 1999 Aug;31(3):185-90.
Auger M, Katz RL, Sella A, Ordóñez NG, Lawrence DD, Ro JY. Fine-needle aspiration cytology of sarcomatoid renal cell carcinoma: a morphologic and immunocytochemical study of 15 cases. Diagn Cytopathol. 1993;9(1):46 51.
Baer SC, Ro JY, Ordonez NG, Maiese RL, Loose JH, Grignon DG, Ayala AG. Sarcomatoid collecting duct carcinoma: a clinicopathologic and immunohistochemical study of five cases. Hum Pathol. 1993 Sep;24(9):1017-22.
DeLong W, Grignon DJ, Eberwein P, Shum DT, Wyatt JK. Sarcomatoid renal cell carcinoma. An immunohistochemical study of 18 cases. Arch Pathol Lab Med. 1993 Jun;117(6):636-40.
Quiroga-Garza G, Khurana H, Shen S, Ayala AG, Ro JY. Sarcomatoid chromophobe renal cell carcinoma with heterologous sarcomatoid elements. A case report and review of the literature. Arch Pathol Lab Med. 2009 Nov;133(11):1857-60.
Gira FA, Barbieri A, Fellegara G, Zompatori M, Corradi D. Dedifferentiated chromophobe renal cell carcinoma with massive osteosarcoma-like divergent differentiation: a singular entity in the spectrum of retroperitoneal calcifying tumors. Int J Surg Pathol. 2010 Oct;18(5):419-23.
