Sarcomatoid Renal Cell Carcinoma

Definition

• Renal cell carcinoma of any type exhibiting at least focal sarcomatoid/spindle cell differentiation

Alternate/Historical Names

• Carcinosarcoma
• Spindled carcinoma

Diagnostic Criteria

• Represents a form of high grade transformation, not a distinct subtype of renal cell carcinoma
  • May occur in any of the standard subtypes of renal cell carcinoma
  • Reported to occur in 5-8% of renal cell carcinomas
    • Less common in our experience
  • Should not be reported as the subtype of renal cell carcinoma
• Requires evidence of epithelial differentiation
  • Concurrent areas of renal cell carcinoma of any type, OR
  • Immunohistochemical positivity for keratin or EMA
    • (Keratin and EMA expression may be appropriate for some sarcomas, including leiomyosarcomas)
• Requires a spindle cell component measuring at least one low power (40x) field
  • May be discrete or intermixed with epithelial elements
  • May be very focal
• Most common patterns are fibrosarcoma and malignant fibrous histiocytoma
  • Rare cases reported with patterns of rhabdomyosarcoma, chondrosarcoma, osteosarcoma and hemangiopericytoma
  • Pattern does not appear to affect prognosis
• Grade of sarcoma is not clinically significant
  • May range from low to high
    • Based on cellularity, atypia, mitotic figures
• See Classification/Lists in menu at left for links to specific carcinoma subtypes

John P Higgins MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting:: January 24, 2011

Supplemental studies

Immunohistology

Differential Diagnosis

• Primary renal sarcomas
• Sarcomatoid urothelial carcinoma
• Angiomyolipoma

Primary renal sarcomas

• Must not have associated epithelial components
• 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)
    • Note that oncocytomas can infiltrate fat and exhibit vascular invasion without affecting prognosis (Perez-Odonez)
• Critical/controversial points in staging of RCC include:
  • pT3a is defined as extension into perirenal fat
    • This requires actual touching of fat, preferably 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)

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

Classification / Lists

Renal epithelial neoplasms

• Classical types
  • Clear cell (conventional) renal cell carcinoma
  • Multilocular renal cell neoplasm of low malignant potential
  • Papillary renal cell carcinoma
  • Chromophobe renal cell carcinoma
  • Collecting duct carchinoma
  • Renal cell carcinoma unclassified
  • Oncocytoma
  • Papillary adenoma
  • (Sarcomatoid)
• Newer variants and types
  • Renal medullary carcinoma
  • Mucinous tubular and spindle cell carcinoma
  • Tubulocystic carcinoma
    
  • Hereditary leiomyomatosis associated renal cell carcinoma
    
  • MiT family translocation carcinoma
  • Neuroblastoma associated renal cell carcinoma
  • Renal cell carcinoma associated with end stage renal disease
  • Succinate dehydrogenase-deficient renal cell carcinoma
  • Thyroid-like follicular carcinoma of the kidney
  • Clear cell papillary renal cell carcinoma
  • Oncocytic papillary renal cell carcinoma
• Neuroendocrine tumors
  • Carcinoid
  • Neuroendocrine carcinoma

Bibliography

• 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.