Sarcomatoid Renal Cell Carcinoma
Differential Diagnosis
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
