Table 2.

Meta-analysis of Nine Studies of Metastatic PPGLs

		Percent Malignant			Percent
Study	N	Adrenal	Extra-adrenal	Total	Extra-adrenal
Remine et al. 1974	138	9.7% (12/124)	42.9% (6/14)	13.0%	10.1%
Proye et al., 1994	310	11.6% (31/268)	40.5% (17/42)	15.5%	13.5%
Goldstein et al., 1999	99	11.0% (8/73)	23.1% (6/26)	14.1%	26.3%
Mannelli et al., 1999	281	6.7% (17/253)	32.1% (9/28)	9.2%	9.9%
John et al., 1999	95	6.5% (5/77)	27.8% (5/18)	10.5%	18.9%
Edstrom Elder et al., 2003	85	10.0% (7/70)	46.7% (7/15)	16.5%	17.6%
Amar et al., 2005	192	11.4% (19/167)	40.0% (10/25)	15.1%	13.0%
Feng et al., 2011	136	16.6% (17/102)	41.2% (14/34)	22.7%	25.0%
Park et al., 2011	152	9.5% (13/137)	26.7% (4/15)	11.2%	9.9%
Total	1488	10.1% (129/1271)	35.9% (78/217)	13.9%	14.6%