A 42-year-old nulliparous woman presented with a large pelvic mass. Laparotomy showed a 20-cm partially cystic lesion suspended in the omcntum, as well as a smallcr solid mass in the rcctovaginal spacc with a protrusion into the pouch of Douglas. The cystic lesion was excised. The ovarics appeared normal and were conserved. Removal of thc lesion in the rectovaginal spacc was delayed until six wccks later, after the histology had been reviewed. This mass was shelled out easily and the capsule left intact.Thc past history was significant; ten years previously she had been treated, at another hospital for menorrhagia and dysuria of eight months duration. Examination had shown an irregularly shaped uterus, enlarged to the size of a 16-week prcgnancy, and a total hysterectomy was performed for presumed fibroids. Histology showed 'stromal cndornctriosis'.A year after removal of the pelvic recurrence a chcst X-ray showed a ncw opacity in the lcft upper lung ficld. At thoracotomy a 1.5 cm pinkish brown, partly haemorrhagic, wcll-circumscrihcd subpleural lesion was removed with a margin of normal lung. Two months later at another abdominal operation a 2.5 cm recurrence was rcmoved from just to the left of the rectum below thc pelvic peritoneum. Four months later a computed tomography scan of the pelvis showcd recurrent tumour lying behind the bladder and extending out of the pelvis on the lcft in relation to the psoas muscle.At this stagc the patient had undergone a total o f four opcrations for recurrent o r metastatic