Table 4. Pattern of protein nitration in renal tumours: correlation with the nitration of red blood cells and the degree of the inflammatory infiltrate.

	3-Nitrotyrosine immunohistochemistry
Tumour type	Tumour cells	Red blood cells	Inflammatory infiltrate
Oncocytoma	Homogeneous	−	−
Chromophobe RCC	Heterogeneous	+	+
Clear cell RCC
Fürhman I	Heterogeneous	+	++
Fürhman II	Heterogeneous	+	+++
Fürhman III	Heterogeneous	+	+++
Fürhman IV	Heterogeneous	+	+++

3-Nitrotyrosine immunohistochemistry was performed on paraffin sections of three cases of each tumour type. The immunostaining of tumour cells was referred to as ‘homogeneous’ when a majority of cells was stained with the same intensity and as ‘heterogeneous’ when some parts of the tumour were stained and others devoid of any staining. Immunostaining of red blood cells: (−) denotes absent and (+) denotes majority of red blood cells stained.

Semiquantitative evaluation of the inflammatory infiltrate: (−) means absence of infiltrate; (+) denotes a mild infiltrate, (++) a moderate infiltrate and (+++) an abundant infiltrate.