Table 2. Immunohistologic study.

Immunohistologic finding	Typical endometriosis	Atypical endometriosis	p-value	ECA	EAA	p-value
Ki-67	2.36%	14.61%	<0.001*	5.93%‡	22.58%‡	0.004*
BAF250a negative	3%	23.8%	0.004†	9.1%	40%	0.149†
COX-2 positive	96.8%	60%	<0.001†	80%	20%	0.089†

EAA, endometriosis with architectural atypia; ECA, endometriosis with cellular atypia.

^*Mann-Whitney U test; ^†Fisher's exact test; ^‡Average value of the Ki-67 index.