Objective: To evaluate the effect of chocolate cyst fluid on the proli
feration of cultured human endometrioma cells and to assay the concent
ration of transforming growth factor-B-1 in this fluid. Design: Contro
lled in vitro study. Setting: Department of Obstetrics and Gynecology,
State University of New York Health Science Center. Patient(s): Five
women with ovarian endometriomas. Intervention(s): Endometrioma tissue
and chocolate fluid from five different patients were entered in this
study. Main Outcome Measure(s): Endometrioma cell proliferation in cu
lture with and without chocolate cyst fluid. Result(s): Chocolate cyst
fluid increased the proliferation of endometrioma cells compared with
controls. Also, high concentrations of transforming growth factor-B-1
were found in cysts' fluid. Conclusions: Chocolate cyst fluid has a g
rowth-enhancing effect on endometrioma cells. One promoting growth fac
tor is transforming growth factor-B-1. (Fertil Steril(R) 1998; 170:827
-30. (C) 1998 by American Society for Reproductive Medicine.).