**27. Histological features of endometriosis of the nervous system**

There are about 30 cases reported of endometriosis of the sciatic nerve, one case of endometriosis of the lumbar spinal cord and one case of cerebral endometriomas. These cases developed probably by "metastatic" implantation of endometrial tissue, through the perineural lymphatics (Abrao et al, 1999, Ichida et al, 1993).

These lesions occur to postmenopausal women and are multiple nodules usually attached to peritoneum or floating free in the peritoneal cavity. They consist of a central fibrotic or hyalinized core with central necrosis surrounded by lipid laden histiocytes. Occasionally multiple sections will reveal remnants of endometriotic foci, and typical ovarian

Superficial cervical endometriosis is observed in the lamina propria of ectocervix as a solitary or multiple hemorrhagic nodules (endovervix is rarely involved by endometriosis). The predisposing factor is cervical trauma and implantation of endometrioid tissue after surgery. Deep cervical endometriosis is created by the extension of a cul-de-sac lesion and is observed in widespread pelvic endometriosis. Similar mechanisms underlie superficial and

Tubal endometriosis may occur as: a direct extension of endometrial tissue with replacement of tubal mucosa, as a growth of endometrial tissue into the lumen with total occlusion causing infertility and associated with tubal pregnancy and, as post-

Endometriosis of the umbilicus in the absence of previous caesarian section or hysterectomy is described as spontaneous endometriosis and it is caused by lymphatic dissemination of endometrial tissue, through lymphatic vessels extending between pelvis and umbilicus. Umbilical endometriosis may recur after surgical resection (Chen,

There are 21 cases of documented pleural endometriosis involving exclusively the right side of thorax and 17 cases of pulmonary endometriosis. These cases were associated with abdominal endometriosis in one third of the cases and with uterine operations in half of the cases. The development of pulmonary endometriosis suggests an embolic origin of the endometrial implants, while the pleural involvement is explained by the passage of

There are about 30 cases reported of endometriosis of the sciatic nerve, one case of endometriosis of the lumbar spinal cord and one case of cerebral endometriomas. These cases developed probably by "metastatic" implantation of endometrial tissue, through the

**22. Histological features of necrotic pseudoxanthomatous nodules** 

**23. Histological features of superficial and deep cervical endometriosis** 

**24. Histology of the three types of tubal endometriosis** 

**25. Histological features of spontaneous umbilical endometriosis** 

**26. Histological features of pleuropulmonary endometriosis** 

endometrial implants through diaphragmatic lymphatics or defects.

perineural lymphatics (Abrao et al, 1999, Ichida et al, 1993).

**27. Histological features of endometriosis of the nervous system** 

salpingectomy endometriosis, following tubal ligation.

endometriosis co-exists.

1998).

deep vaginal endometriosis as well.
