The importance of histological diagnosis in patients with chronic pelvic pain and laparoscopic evidence of endometriosis

Objective To assess the accuracy of laparoscopic diagnosis of pelvic endometriosis by histological evaluation of biopsies excised from pelvic peritoneal lesions suspicious for endometriosis in patients with chronic pelvic pain. Setting Centre for Endometriosis and Pelvic Pain, St Peter's Hospital, Chertsey, UK, between October 1997 and October 1998. Subjects 62 patients with the presenting complaint of chronic pelvic pain. These patients were included in the study irrespective of previous pelvic surgery or the earlier diagnosis of pelvic endometriosis. Intervention Laparoscopic assessment and excision of peritoneal lesions suspicious for endometriosis. Excision biopsy of all suspected endometriotic lesions was laparoscopically performed using a sculpted tip Nd: YAG laser fibre. All procedures were undertaken under the direct supervision of the same senior laparoscopic surgeon. No major complication was encountered. The biopsies obtained were labelled according to the anatomical site and histologically examined by light microscopy for the presence of endometriosis. Results We took 1-6 biopsies per patient and the total number of biopsies obtained was 150. Biopsies from three patients among the 62 were unsuitable for histological evaluation and were excluded from the study. In 43 patients (73%) there was histological confirmation of endometriosis in all or some of their biopsies. In all the biopsies from 14 patients (24%) there was no evidence of endometriosis, their biopsies comprising other tissues such as fibro-fatty, fibrovascular and fibromuscular tissues. In two patients (3%) all their biopsies showed endosalpingiosis only. The commonest anatomical sites of pelvic peritoneal endometriotic lesions were the uterosacral ligaments, the pouch of Douglas, the medial broad ligaments, the intestinal serosa, and the ovarian fossae, respectively. Conclusions The diagnosis of pelvic endometriosis in patients with chronic pelvic pain should be supported by excision biopsy and histological assessment, as the laparoscopic diagnosis is not always accurate. This would direct the clinician to the possible aetiology of the chronic pelvic pain and is of great value in counselling and planning future management for the patients.