Objective: To initiate in vitro cultures of separate stromal and epithelial elements from endometriotic tissue and to compare the characteristics of these cells with those of cultured endometrial cells.
Design: The study involved testing the viability of a culture system for endometriotic tissue and examination of the phenotype of the cells.
Setting: Fresh tissue samples were collected from the operating theater and transferred to the tissue culture laboratory.
Patients, participants: Twenty patients undergoing laparotomy for endometriosis and patients undergoing surgery for benign conditions were recruited.
Interventions: Endometrium and endometriotic tissue were separated, cultured in vitro, and labeled by indirect immunofluorescence with monoclonal antibodies against cytoskeletal components and epithelial mucins.
Main outcome measures: Endometriotic cells have been maintained in vitro and found to resemble endometrial cells closely.
Results: With respect to the staining patterns for cytokeratins 18 and 19, vimentin, and three different epithelial mucins, cultured cells from both endometrium and endometriotic tissue had similar properties. Cytokeratins were located in epithelial cells, and vimentin was expressed in both stromal and epithelial cells. The antimucin antibodies all gave distinct patterns of intracellular staining of epithelial cells.
Conclusions: Our results indicate a close similarity between cultured stromal and epithelial cells from endometrium and endometriotic deposits. Culture of these cell populations will permit study of their properties and interactions and may provide some insight into the cause of endometriosis.