Cytologic diagnosis of peritoneal fluids. Applicability to the laparoscopic diagnosis of endometriosis.

Objective: To determine the accuracy of cytologic examination of laparoscopically obtained peritoneal fluid in the diagnosis of endometriosis.

Study Design: This investigation analyzed 50 laparoscopic fluid specimens received over a three-year period. Retrospective cytologic findings were correlated with clinical history and laparoscopic diagnoses. Touch preparations were also collected from necropsies to develop cytologic criteria necessary to distinguish endometrial cells from mesothelial cells.

Results: The presence of hemosiderin-laden macrophages in peritoneal fluids was more specific but less sensitive than the presence of endometrial cells for the diagnosis of endometriosis.

Conclusions: In women undergoing laparoscopy to detect endometriosis, the identification of endometrial cells alone in peritoneal fluids may not be sufficient to render a definitive diagnosis of endometriosis. However, the presence of hemosiderin-laden macrophages in this population should alert the cytologist to that possibility.