A serial section study of visually normal pelvic peritoneum in patients with endometriosis.
 Defined criteria were used to select small samples of visually normal study peritoneum for serial section light microscopy in 45 patients with biopsy-proven endometriosis and 10 patients without endometriosis.
 A glandular element compatible with possible endometriosis was found in only 1 patient.
 Visually normal peritoneum does not harbor a high prevalence of invisible microscopic endometriosis.
