Multicystic benign mesothelioma of the peritoneum presenting as postmenopausal bleeding and a solitary pelvic cyst--a case report.

BACKGROUND: All non-invasive diagnostic algorithms suffer from diagnostic uncertainty in discriminating benign from malignant adnexal masses. CASE: We present a case where the identification of a large solitary multiloculated pelvic cyst in a woman with postmenopausal bleeding was shown to be multifocal multicystic benign mesothelioma (MBM) of the peritoneum at laparotomy. CONCLUSION: We wish to alert gynaecologists of this rare association and the unique appearance of mesothelioma lesions, which many would not instantly recognise. There is a lack of consensus on the treatment and follow-up of MBM. Most authorities consider curative treatment of MBM is achievable through complete disease cytoreduction (peritonectomy) as carried out in the case.