Papillary renal cell carcinoma

Definition

By definition, at least 50% of the tumour shows true papillae.

Epidemiology

Papillary tumours constitute 7 to 15% of all renal cell carcinomas. There is an association with renal cortical adenomas. A hereditary form is associated with mutations of the c-met oncogene.

Radiology

Large tumours may appear cystic.

Macroscopic appearances

Small tumours may have the appearance of flecks of gold in a haemorrhagic background. There may be apparent necrosis,which is in fact due to macrophages filling the papillae.

Histopathology

The papillae may appear as spherules or tubules, lacking fibrous cores. Conversely, cores may be apparent and may be distended with macrophages.

The two most common subtypes are composed of:

• Type I: micropapillary; basophilic cells with scant cytoplasm covering short thin vascular stalks. Infiltration by foam cells is more common in this subtype³. There is a strong male predominance³.

• Type II: macropapillary; eosinophilic cells with abundant cytoplasm covering oedematous or thick stalks.

• An oncocytic variant has been proposed.

• There is also probably a solid variant⁸. Solid micronodules may represent abortive micropapillae⁸. These also show the characteristic trisomies of chromosomes 7 or 17⁸.

Intracytoplasmic haemosiderin may be abundant. Rare psammoma bodies may be present.

Immunohistochemistry

	Pancytokeratin KL-1	25/27 (diffuse positivity of more than 80% of tumour cells; 17, strong positivity of 50-80% of tumour cells; 6, heterologous positivity of less than 50% of tumour cells; 2: study by tissue microarray)2
	34bE12	7/27 (diffuse positivity of more than 80% of tumour cells; 2, strong positivity of 50-80% of tumour cells; 4, heterologous positivity of less than 50% of tumour cells; 1: study by tissue microarray)2
		solid variant: 0/68
	Cam5.2	25/27 (diffuse positivity of more than 80% of tumour cells; 19, strong positivity of 50-80% of tumour cells; 5, heterologous positivity of less than 50% of tumour cells; 1: study by tissue microarray)2
	CK7	12/27 (diffuse positivity of more than 80% of tumour cells; 8, strong positivity of 50-80% of tumour cells; 3, heterologous positivity of less than 50% of tumour cells; 1: study by tissue microarray)2
		micropapillary: 15/15 (diffuse positivity)3, 48/61 (moderately or strongly positive)4 macropapillary: 4/19 (focally positive)3,6/304 solid variant: 6/68
	CK19	micropapillary: 15/153 macropapillary: 10/193
	EMA	18/27 (diffuse positivity of more than 80% of tumour cells; 12, strong positivity of 50-80% of tumour cells; 3, heterologous positivity of less than 50% of tumour cells; 3: study by tissue microarray)2
		solid variant: 6/63
	MOC31	3/27 (diffuse positivity of more than 80% of tumour cells; 2, heterologous positivity of less than 50% of tumour cells; 1: study by tissue microarray)2
	BerEP4	18/27 (diffuse positivity of more than 80% of tumour cells; 9, strong positivity of 50-80% of tumour cells; 4, heterologous positivity of less than 50% of tumour cells; 5: study by tissue microarray)2
	RCC Ma	17/27 (diffuse positivity of more than 80% of tumour cells; 16, strong positivity of 50-80% of tumour cells; 1: study by tissue microarray)2, 13/145
	CD10	16/27 (diffuse positivity of more than 80% of tumour cells; 6, strong positivity of 50-80% of tumour cells; 3, heterologous positivity of less than 50% of tumour cells; 7: study by tissue microarray)2, 13/145, 19/20 (moderate or extensive in 7/8 type II but in only 5/12 type I)9
	E-cadherin	12/27 (diffuse positivity of more than 80% of tumour cells; 4, strong positivity of 50-80% of tumour cells; 3, heterologous positivity of less than 50% of tumour cells; 5: study by tissue microarray)2
	CD15	11/27 (diffuse positivity of more than 80% of tumour cells; 7, strong positivity of 50-80% of tumour cells; 2, heterologous positivity of less than 50% of tumour cells; 2: study by tissue microarray)2
	Vimentin	17/27 (diffuse positivity of more than 80% of tumour cells; 8, strong positivity of 50-80% of tumour cells; 8, heterologous positivity of less than 50% of tumour cells; 1: study by tissue microarray)2, 6/76
	Dolichos biflorus agglutinin	micropapillary: 11/153 macropapillary: 2/193
	b defensin-1	7/76
	parvalbumin	5/76, 0/177

Papillary carcinomas frequently co-express TCC Ma and BerEP4².

Cytogenetics

Trisomies of chromosomes 7 and 17 are common.

Differential diagnosis

• The solid form may resemble metanephric adenoma.

• Conventional renal cell carcinoma with focal papillary areas.

• High grade tumours need to be differentiated from collecting duct carcinoma.

Prognosis

Low grade tumours have an excellent prognosis, high grade tumours a poor prognosis. Metastases are usually to lymph nodes.

• Micropapillary subtype: five year survival of 87%³.

• Macropapillary subtype: five year survival of 46%³.

References

¹ Renshaw, A. A. (2002). "Subclassification of renal cell neoplasms: an update for the practising pathologist." Histopathology 41(4): 283-300.

² Pan CC, Chen PC,Ho DM. The diagnostic utility of MOC31, BerEP4, RCC marker and CD10 in the classification of renal cell carcinoma and renal oncocytoma: an immunohistochemical analysis of 328 cases. Histopathology 2004; 45:452-9

³ Ono, Y., Ito, T., Tsujino, S., Aizawa, S. and Suzuki, M. [A study of papillary renal cell carcinoma. Clinicopathological, immunohistochemical features and its typing]. Nippon Hinyokika Gakkai Zasshi 1997;88:587-95.

⁴ Delahunt, B. and Eble, J.N. Papillary renal cell carcinoma: a clinicopathologic and immunohistochemical study of 105 tumors. Mod Pathol 1997;10:537-44.

⁵ Avery, A.K., Beckstead, J., Renshaw, A.A. and Corless, C.L. Use of antibodies to RCC and CD10 in the differential diagnosis of renal neoplasms. Am J Surg Pathol 2000;24:203-10.

⁶ Young, A.N., de Oliveira Salles, P.G., Lim, S.D., Cohen, C., Petros, J.A., Marshall, F.F., Neish, A.S. and Amin, M.B. Beta defensin-1, parvalbumin, and vimentin: a panel of diagnostic immunohistochemical markers for renal tumors derived from gene expression profiling studies using cDNA microarrays. Am J Surg Pathol 2003;27:199-205.

⁷ Martignoni, G., M. Pea, et al. (2001). "Parvalbumin is constantly expressed in chromophobe renal carcinoma." Mod Pathol 14(8): 760-7.

⁸ Renshaw, A.A., Zhang, H., Corless, C.L., Fletcher, J.A. and Pins, M.R. Solid variants of papillary (chromophil) renal cell carcinoma: clinicopathologic and genetic features. Am J Surg Pathol 1997;21:1203-9.

⁹ Langner, C., M. Ratschek, et al. (2004). "CD10 is a diagnostic and prognostic marker in renal malignancies." Histopathology 45(5): 460-7.

This page last revised 10.1.2005.

©SMUHT/PW Bishop