c-Maf

c-Maf is the cellular homologue of the avian retroviral transforming gene v-Maf. c-Maf is a member of the basic leucine zipper family and the AP1 superfamily. Mice engineered to over-express c-Maf in B-cells develop multiple myeloma, those over-expressing c-Maf in T-cells develop T-cell lymphomas.

5%-10% of patient with multiple myeloma have a t(14;16)(q32;q23) translocation fusing the c-Maf gene to the immunoglobulin heavy chain gene. Other cases of myeloma appear to activate c-Maf by other mechanisms, with over-expression in 50% of all myelomas.

Immunohistochemical expression

Staining is nuclear.

	Normal lymph nodes	some centroblasts within germinal centres positive
	Angioimmunoblastic T-cell lymphoma	23/31 1
	Adult T-cell lymphoma/leukaemia	3/111
	Multiple myeloma	7/81
	Peripheral T-cell lymphoma	4191
	Mycosis fungoides	011
	Anaplastic large cell lymphoma	0111
	Extranodal NK/T-cell lymphoma, nasal type	0101

Diagnostic utility

Possibly useful in the diagnosis of Angioimmunoblastic T-cell lymphoma

References

1 Murakami YI, Yatabe Y, Sakaguchi T, et al. c-Maf expression in angioimmunoblastic T-cell lymphoma. Am J Surg Pathol 2007; 31:1695-702

This page last revised 31.12.2007.